Saturday, March 24, 2007

Intermittent NO SPARK on 1994 Ford Taurus with 3.0L engine: NO CODES




Question:

What could cause my 94 Ford Taurus to quit intermittently? When I scanned it, there is no code and even after I replaced the ignition module, same thing happens. This symptom can happened anytime, anywhere which makes this car unsafe to drive!

ATS Adviser:
If you have already replaced the ignition module, most likely the pickup coil inside your distributor is the culprit. To check, take the distributor out (make sure you mark the distributor housing and point the rotor to #1 position) and measure the coli resistance in ohms. Sometimes, you need to apply a heated air to the coil like a hair dryer. To get the right specs in ohms, contact ATS.

Thursday, March 22, 2007

No spark and no fuel on 1991 Mitsubishi with 4 cylinder engine: NO CODES




Question:

My sister's car quit yesterday and when I checked it, there was no spark on the plug wires and no fuel going to the throttle body. There was no code when I scanned it but the distributor has the power going to it. I replaced the distributor with a rebuilt one but the same thing happened: no start!!! This is getting very frustrating and I need your help. Thanks.

ATS Adviser:

Based on your symptons, I would check the power and ground supplies going to the ecm (computer). First of all the ecm grounds your distributor in order to work and most likely, that is the culprit however, check your ground and power supplies first as laid out in ATS courseware. If you need the ecm diagram, just let me know.

Wednesday, March 21, 2007

P0420 code on 1998 Honda Civic with 1.6L engine




Question:

This car has an intermittent code P0420- catalyst efficiency low coming on and when I checked the downstream oxygen sensor, it was responding properly. I decided to replace the CAT (catalytic converter) buying an aftermarket one from a local muffler shop so I can save money (the CAT from the dealership is very expensive). After road testing, the light came back. The muffler then advised me to replace the downstream oxygen sensor but it did not fix the problem. What should I do?

ATS Adviser:

There is high rate of failure when using aftermarket CAT and most garages recommend using only OEM CAT from Honda especially on 1996 models and up. If you put an oem CAT on this, the code will stop coming back provided the oxygen sensor wires are not shorting out. Also, when testing the oxygen sensors for this engine, the upstream sensor is used for engine fuel management whereas the downstream sensor is used to monitor CAT efficiency.

Monday, March 19, 2007

Cruise control won't work on 1998 Chevy Cavalier: No codes




Question:

This is my grandma's car and she complained to me that the cc (cruise control) suddenly won't work after making a long highway trip. I checked for codes but could not get one. A friend mechanic advised me to replace the CC module or control unit but my sister has a similar car and I substituted her part to this car. This did not work either and I am running out of hair trying to figure this out. Suggestion?

ATS Adviser:

Before you get deeper on this problem, try checking the 2 rear brake lights for proper operation. A lot of times, a broken brake bulb can kill your cc and all you do is to check the bulb socket or the bulb itself. If they are OK, check the 3rd brake light too in your rear windshield. If these don't fix this, let me know so I can send you the complete wiring diagram of the cc circuit so you can check the ground and power supplies.

Sunday, March 18, 2007

Battery goes dead if left after 5 days on 2001 Nissan Pathfinder: No codes




Question:

Why would my battery goes dead if I leave it parked for 4-5 days? There is no code when I had it scanned at a local parts store and I also replaced the battery. Also, on the 3rd day, I can hear the starter laboring before the engine starts. This only started happening after my son installed an aftermarket remote starter 1 month ago. Please help.

ATS Adviser:

It's good you mentioned the aftermarket remote starter because there are lots of problem going on with them these days. It is recommended that when installing a remote starter that you get it from the dealer and they can even hook it up correctly. If the wiring connections are not right, it can create a battery drain causing your symptoms. To check, disconnect this aftermarket remote starter wiring connection and monitor your starting system again. If this problem stops, then that is the culprit.

Saturday, March 17, 2007

P0133 Code for 98 Saturn with 1.9L engine.




Question:

This car has a code P0133- 0xygen sensor signal slow and when I tested it using a voltmeter, I got 0.4 volt with key on engine off. When started and warmed up, the reading was fluctuating between 0.1 volt to 0.9volt as it should be. However, even after I changed the sensor, the code returns and got the SAME reading. Is this a computer problem?

ATS Adviser:

Before you condemn the computer, check the ground wire for the oxygen sensor located on the transmission mounting stud. If OK, I would check the oxygen sensor wirings at the ecm itself. There is a chance the wires could be open or shorted thereby givig you the code. If you still get the same readings, then you can also check the ground readings of the ecm and bring the same to the dealer for replacement or re-programming. ATS can provide you with the ecm wiring diagram so you can check all the pin voltage readings.

Tuesday, January 23, 2007

Battery light is on and alternator not working on 1997 Odyssey Honda with 2.2L engine: No codes




Question:


My wife's 1997 Honda Odyssey battery light is on all the time and the alternator won't charge. I replaced the alternator with a rebuilt one from our local parts store but the problem is still there. A friend mechanic told me to replace the ecm (computer) but I am not sure if this will fix the problem. Can you help?

ATS adviser:


There is an electrical load detection (ELD) unit located at the fuse box under the hood. Check the pin wire #2 with grn/red color and see if it is connected to the pin#16 in your ecm. This is a control wire from the ecm to your alternator. To check, run a jumper wire between those pins and if the alternator starts to charge, replace the alternator. Finally, if you bought the alternator locally and not from Honda, I guarantee your alternator will not work.

ATS tip:

When testing the LED unit, make sure the ground wire at pin#1 is clean and secure. To get the wiring diagram for the charging system, contact ATS.

Monday, January 22, 2007

P0303 misfire code for 1997 Ford Wind Star with 3.8L engine




Question:

This 1997 Wind Star is having a misfire code after the engine is warmed up. When scanned there is no coolant sensor code except this misfiring code. The engine has a lot of mileage but when we checked the compression, readings are all above 140 psi. No engine coolant was found in the oil and I think the engine is fine. testing the vacuum confirms that the reading is well above normal.

Testing the injectors shows the same reading and when I checked the spark quality while idling, I have a steady blue strong spark. I am now inclined to suspect that we might have a computer problem. Do you agree?

ATS Advisor:

There are a few tests you can do on this code: 1.) try switching the plug wires and see if the misfire code will change to another cylinder. 2.) did you clean the mass sensor? usually this will not cause a misfire code. 3.) tried disconnecting the egr valve? if misfire stops, then egr system is faulty. 4.) if all of the above fails, remove the intake plenum at the intake manifold and most of the time, the seals and O rings for this plenum leaks causing a misfire code when hot.

Sunday, January 21, 2007

Car hesitates on 1999 Cavalier with 2.2L engine: No codes




Question:

I have a 1999 Cavalier and lately, I have an intermittent hesitation and misfiring and the check engine light will come on in the dash. However, if I scanned it, my scanner will not communicate with the engine computer (ecm).
What do I do?

ATS Advisor:

There is common cause for this problem and it is attributed to the poor location of the ecm. If you look under the front fender of the car and remove the cover, you will see the ecm. A lot of times, because it is too close to the ground and rain water when you are driving, the wire terminals to the ecm will be corroded. When that happens, the wires will be covered with "green stuff" and later the wire can have a poor contact or even break. Try wiggling the wires to the ecm and find which wire is broken. Repair if necessary.

If the ecm will still have no communication with your scanner, remove the ecm and test all the ground and power supply wires as per ATS past newsletters (testing ecm). If the readings are normal and reference voltage is erratic, replace the ecm.

ATS Tip:

To get a detailed wiring diagram of your ecm, please contact ATS.

Saturday, January 20, 2007

P0402 code for 1999 Nissan Altima with 2.4L engine




Question:

Have this code P0402-egr control back pressure transducer valve on my Altima and when I tested it, found the egr valve sticking. Replaced the valve and also cleaned the passage tubing going to it. After resetting the code and road testing it, the code light went out. however, after a week of using, the same code came back. I re-check the egr valve and I cannot find anything wrong. Please help.

ATS Advisor:

When testing your egr system, try these:

Check all your egr vacuum hoses for cracks and connection

There is a restrictor inside the vacuum hose for the EGRC-BPT valve, that cam be tested for dirt restrictions due to carbon

The egr valve flow can be tested by lifting the spindle with your finger during idle and the rpm should go lower.

If the above code persists, replace the egrc-bpt valve next to the egr valve.

Friday, January 19, 2007

Code P0301 on 2001 Pontiac Grand Am with 2.4L engine




Question:

My 2001 Grand Am has a misfire code P0301 when scanned. The engine was also quitting at stop lights. Initial repairs included replacing the spark plugs that included the ignition coil. After doing all of these, misfiring is still present and I am now thinking of replacing either the ignition module or the engine computer. Any suggestion?

ATS Advisor:

The most common cause of this misfiring is a shorted ignition coil housing. When you replaced the spark plugs, the housing should been checked for heat burns on the housing which will verify such condition. shown on top is a picture of the housing. If you invert it, most heat burns will occur between the spark plug mounting holes.

Thursday, January 18, 2007

Code 32 on 1990 Corsica with 3.1L engine




Question:

This 1990 Chevy Corsica has a code 32-egr system fault after I scanned it with OBD1 scanner. When I checked the egr system, I found that I have an egr electric solenoid instead of an egr valve. How do I proceed to test it?

ATS Advisor:

To check the egr solenoid is quite simple. start and run your engine at idle and put a jumper wire on each of solenoid 3 wires. When you do this, each solenoid will be activated causing it to open up and should cause your idle rpm to change. If all 3 solenoids do not make any changes, stop the engine and remove the egr solenoid. When removed, check first for the opening where the solenoid was mounted. If the hole is clear of carbon, replaced the solenoid, otherwise clean the egr passage hole.

ATS can supply you the wiring colors of each egr solenoid wire.

Friday, January 12, 2007

Serpentine belt installation for 2003 GM p/up truck: No codes




Question:

This truck's engine serpentine belt was sqealling and before I could replace it, it broke on me, how do you replace it?

ATS Advisor:

If you open your hood compartment of your truck (see picture) you will see the diagram of the serpentine belt routing. You can follow that and when you buy a new one, the package of the belt will also show a diagram for it. Make sure you give the parts store the accessories that you have like AC so they can give you the right lenght of belt.

Sunday, January 07, 2007

After market water pump for 2003 Honda Civic has to be changed twice in the last 3 months: No codes




Question:

Why would my water pump started to leak 2 weeks after I replaced it and AGAIN after almost 3 months? I bought this water pump from a local parts store and I also flushed the cooling system to make sure the coolant circulating is clean (engine has over 100k miles). Do I need to use a special coolant for this vehicle? Your insights would be highly appreciated.

ATS Advisor,

First of all, stay away from after market parts when dealing with imported vehicle like Honda. You can buy an OEM (original) part from the dealer and you can avoid all this head aches. when replacing the coolant, use the one recommended by the dealer and mix it 50-50 with water. If you need more assistance, just contact ATS.

Friday, January 05, 2007

P0123 TPS Code for 2000 Jeep Sport Cherokee with 4.0L engine




Question:

This 2000 Jeep Sport Cherokee has this check engine light coming on and when scanned, a code P0123-tps voltage abnormally high showed up. Ever since this happened, my cruise control quit working and the engine keeps stalling making it difficult to drive in heavy traffic. Measuring the tps voltage using ATS wiring diagram showed the tps is defective. We replaced the tps sensor but it did not fix anything. Thinking it might be the computer, we replaced that too and STILL the same code! Please help!

ATS Advisor:

This is a common problem and you should have contacted ATS before you replace those parts. The problem here is a faulty clock spring hooked up to your steering column. What is happening is the clock spring circuit is shorted and it is also connected to your tps circuit. To test, unplug the connection to the clockspring and your tps should work. Most of this problem is usually solved by replacing the clock spring. If the clock spring is fixed, it will fix the cruise control also.

ATS Tip:

A step by step procedure in replacing the clock spring is available from ATS if you are a member.

Tuesday, January 02, 2007

P0171 and P0174 codes for 2000 Hyundai XG300 with 3.0L engine




Question:

This 2000 Hyundai XG300 runs pretty good but 3 days ago, the check engine light showed up accompanied by codes P0171-Bank 1 system too lean and P0174-Bank2 system too lean. My vacuum reading looked normal and I did a quick tune up like replacing all filters and spark plugs. Since the oxygen sensors have not been replaced since the car was new, I replaced both the upstream sensors. The downstream sensors (after the CAT) are not used to monitor engine fuel mixture so I left them alone. However, after doing all of these, the light came back with the same code. Suggestions?

ATS Advisor:

The most common cause of this problem is a dirty or faulty mass sensor. You can service that by cleaning the sensor wire elements as per ATS course. If you see any improvement after servicing but the code returns after a few days. Replace that sensor too. In case this fix will not work, here are other areas to explore:

Are you using premium gasoline? It would help if you it and may also improve performance.
Have you done fuel chemical tune up? If the engine has too many miles, the injectors could build up varnish and ultimately carbon in the combustion chamber causing this lean condition.
Adding chemical additive to your fuel tank can help remedy this. however, if the code persists, have the injector serviced by a garage.

Monday, January 01, 2007

Code 41 with severe stalling on 1993 Dodge Caravan with 3.3L engine

Question:

My minivan has poor power accompanied by hesitation on acceleration and stalling on stop signs. When scanned, I have code 41. I have checked the engine for mechanical condition and seem OK. Using your ecm test, I found the engine acting up when the ecm is tapped with a rubber mallet. I decided to replace the ecm and it worked good for a couple of days. After that, the problem returned with the code 41. Please help.

ATS Advisor:

The first thing I would check here is your alternator. There are a lot of reports indicating this is a common problem especially on high mileage minivan with this model. Check the alternator for proper ground or have it tested for proper output. If this won't fix it, have the bcm tested also for ground connections. If you read my earlier blog, bcm testing is discussed extensively. Always reset the ecm every time you perform any repair.

Sunday, December 31, 2006

No HEAT in truck cab for 2000 Durango: No Codes







Question:

I have driven this 2000 Dodge Durango truck since new and starting last week, my passenger side carpet under the dash is wet with coolant fluid. When I drove the truck, a foggy smoke came out of the dash vents. Reading your ATS course, I suspect my heater core is toast and needs replacement. Is this a job I can do?

ATS Advisor:

I believe this truck has an AC and if you do, the heater core is embeded inside the evaporator housing which is located in the front passenger side under the dash. To remove, the evaporator housing must be drained first of freon and then you can remove the housing. Attached is an example of the truck cab showing the passenger side. Make sure to mark and label all the parts that you remove and always compare the heater core housing that you will buy.

Once installed, you can put back the freon that you remove or have a garage evacuate the AC systen for you to prevent introduction of moisture to your AC. If you ca do this, you should be able to save money in the replacement of your heater.

Saturday, December 30, 2006

No Start on 2000 Dodge Intrepid with 2.7L engine: No codes

ATS Question:

My wife's car suddenly quit on her while she stopped for groceries. She had it towed to our garage so I can check it. I found the engine with no spark but I could not test the injectors because there is no room for it. Electronically, I tested the asd relay and the ignition coil and both seemed to have good power and ground. I am now at a loss on how to proceed to check the problem. Do you have any suggestion?

ATS Advisor:

You are very lucky because this problem is very common on 1999-2000 models. All you do is unplug the camshaft sensor and try starting again. You might have to be patient because it requires long cranking but it should start. When it does, observe these: if it starts without making a noise in the engine, the culprit is usually the camshaft sensor. If it starts but making a lot of engine noise, the timing chain is usually the problem which requires the opening of the front timing cover.

Tip:

To get the exact location of all the above components, contact ATS if you are a member.

Monday, December 11, 2006

No spark for 1992 Olds ninety Eight with 3.8L engine: No Codes




Question:

My car quit on me yesterday and following ATS course, I found it has no spark. As per your lesson, this problem is caused by crank sensor and ignition module. I first replaced the crank sensor and found still no spark. Went and got a new ignition module and same thing happened. But after spending all these money for parts, I still have no spark? What am I doing wrong? Is my engine computer buggered up too?

ATS Adviser:

First of all, although ATS fixes tells you to suspect both crank sensor and ignition module, there are a few tests involved before replacing those parts. Examples:

Did you check if the crank sensor has proper ground and power supplies? If you requested the ignition wiring diagram, you can see the ground and power supply wires. Always go to the basic: Ground wires should read 0.250 volt or less with key on engine off. Power wires always give you around 12 volts with key on engine off.

These simple tests will tell you if there is a problem with the sensor or ignition coil. The same is true if the wirings connected to them. Those parts might be OK but if the wires are shorted because the insulation is bare, your new parts will not work still.

Finally, a lot of local parts stores can test those parts for you and they can tell if the parts are OK or not. If they say the parts are tested OK, then it gives you a red flag to test the wires or the ecm (engine computer). Again to test the ecm, all you do is test what? The ground and power supply readings at the terminal of the ecm with key on engine off PLUS, the reference voltages. This is the most basic tests of ATS troubleshooting and if you use this method, you will solve about 90% to 95% of engine electronics problem.

ATS Tip:

When testing your wires, use wiggle tests and wiring diagram to trace the shorted wire.

Friday, December 01, 2006

Boosting your battery cables can be deadly...shuts down whole systems: No Codes




This is just a reminder for everybody during this cold weather

When boosting your vehicle battery, remember these:

Connect cables colored RED to RED or red cable to red post at battery (positive)
Connect cables colored black to black or black cable to black post at battery (negative)

Always connect the positive cable first and negative cable last

Always disconnect the black cable first and red cable last.

Shown in the picture is a 2005 Altima with a blown cable terminal fuse after the cables were connected wrong. Problem? Fuse comes integral with the positive cable. now you have to buy the positive cable assembly. What a waste of time and money! Finally, here is another drawback in this Altima...the whole engine shuts down and cannot be re-started until you changed the fuse/positive battery cable (available ONLY from the dealer of course).

Wednesday, November 29, 2006

Code P0302 causing misfire for 1996 Pontiac Grand Am with 2.4L engine




Question:

Four days ago, my Grand Am started misfiring and when I scanned it, I got code P0302 cylinder #2 misfire. Using your earlier advice, I removed the top valve cover and run my own plug wires and switched #2 cylinder with #3 cylinder but the misfire stayed at #2. Switching the ignition coils also made no difference. Because the vacuum hose going to the fuel regulator was wet, I changed the fuel regulator and again made no difference. All the compression readings were over 200 psi and I am losing my wits on what to do next. Your help will be much appreciated.

ATS Adviser:

Since you got the valve top cover out, you might as well do a balance injector test as described in ATS Course. Another quick way to do this is to switch injector #2 to another injector like #4. Then make sure the engine is warmed enough and see if the misfiring will remain in #2 cylinder. If it moves to cylinder #4, you know pretty well that the problem is the injector.

ATS tip:

The fuel regulator although defective in your case, will not cause misfiring. It will make your engine fuel mixture to flood or rich though and cause hard long starts.

Monday, November 27, 2006

Code 181 for 1994 Ford Escort 1.9L accompanied by hesitation and cutting out.


Question:

My mother's Ford Escort would hesitate only when running at highway speeds as if the engine is running out of gas. When this happens, the engine would also stall and finally quit. It will re-start but it has no power. She had the IAC (Idle Control) valve replaced but the problem remains and she asked for my help. I plan to do a major tune up like spark plugs, wires and fuel filter. What bothers me though is when I scanned it, it has code 181 which showed cruising rich and bank 1 lean. Is this problem serious? Can I fix this myself?

ATS Adviser:

First and foremost, check first if you have a vacuum leak which can cause your engine to run lean. Next is to check the voltage readings of your oxygen sensor and see if it fluctuates (see ATS courseware). This sensor seems to be a common problem on this model especially with this code and symptom of hesitation. You can also check these:

1.) Service the mass sensor for dirty wire elements
2.) Check the fuel regulator for diaphragm fuel leakage
3.) Check pcv valve for crack that would cause vacuum leak

You should be able to do these checks by yourself if you read the ATS lessons given to you but I would concentrate your effort to check if the voltage reading of the oxygen sensor is not stuck (this will show that the sensor is defective).

ATS Tip:

A bad running oxygen sensor can disrupt your fuel mixture and would cause hesitation and loss of power.

Thursday, November 23, 2006

P0340 code for 1997 Toyota Camry with 2.2 L engine




Question:

My uncle's 97 Camry has the dash check engine light coming on all the time. Found code P0340 which stands for camshaft position sensor fault. He changed the camshaft sensor and the engine ecm (computer) but the light would come up after driving it for a few miles. He asked me to help him and I just want your assistance before I see him. Note: This vehicle has a lot of mileage on it.

ATS Advisor:

If the vehicle has too many miles and the timing belt has not been replaced, most likely the belt is either loose or has skipped a tooth. When this belt is loose or out of timing, the ecm will get an erratic signal from the camshaft sensor and will trigger this code. This is usually occur with rough idle and lost of power. Try this first and if this won't work, pull out the distributor and check for worn drive gears.

ATS tips:

If timing belt is out of timing, the vacuum reading is usually low (15 inch or lower) accompanied by low compression reading.

Instructions for changing the timing belt are available from ATS if you are a member.

Wednesday, November 22, 2006

BCM (body control module) Testing Summary




When performing test for your body control module (bcm), here are some quick tips in testing this module:

Get hold of the bcm wiring diagram from ATS. Using the bcm diagram, you can identify all the components that being controlled by the bcm by using the wiring colors associated with the part or component. A lot of times, the location of the component is described in the wiring diagram. BCM components usually include lights, power mirror, window and door locks, anti-theft, windshield wiper system, radio, instrument cluster, horn, all vehicle openings like trunks, defogger, power steering, AC, cruise control and other accessories.

The first test of the bcm is using a scanner. It will tell you right away which part of the bcm system is malfunction. It can also isolate the particular circuit in the bcm to narrow down your test. Remember: bcm code is not the same as the engine code.

To test the bcm, start by checking the ground pins for voltage which must not be higher than 0.250 volts. If it does, it means there is a short in the wires or one of the components. To verify, unplug the components one of the time until the voltage reading returns to normal.

Make sure all connections to the bcm and components are tight and not corroded.

The BUS plus and minus communication pins at the bcm can be checked and it should measure about 2.5 volts (ask ATS for the exact voltage for your vehicle) with key on. If none or higher voltage reading, it indicates an open wire or defective bcm or component. Again try to unplug the component one at a time to test.

ATS tips:

When working with bcm, always read all the blog posts by searching the word "bcm" on the top left corner bar of this blog and click "search this blog" beside it.

BCM when replaced needs to be reprogrammed by the dealer when bought new. When buying one from the salvage yard, make sure it is the same match for your vehicle. Sometimes, the bcm does not include the alarm system and can cause future problems.

Monday, November 20, 2006

P0303 code for 1998 Ford Taurus with 3.0L engine.




Question:

My check engine light keeps coming on and got a code P0303 misfiring code on cylinder #3. I checked the compression on this cylinder and it is comparable with the rest. I have no vacuum leak and got 18 inch when I measured it. I swapped the injectors from #3 to #1 cylinder and after a week, the code still returned for #3. Finally, this code is also intermittent and I am about to bring it to the dealer if you have any suggestion.

ATS Adviser:

Going by ATS database, one fix that you might have missed is the ignition coil pack. Have you tried switching the plug wires too? If the coil pack is borderline defective, it will run OK and might test well if you measure it with a voltmeter. However, if it is used for a few days especially under load, it might start to falter and show you the code. That would be the test I would do if I were you before going to the dealer.

ATS Tip:

You can also use an electric air heater and apply it to the coil and see if the part will fail.

Saturday, November 18, 2006

1997 FORD F150 P0401 EGR Flow code with 5.9L engine




Question:

As per your ATS instruction manual, I changed the egr valve, dpfe sensor, egr solenoid including the blowing of air passages of the egr system of this engine yet this same code keeps coming back. Am I missing something? I also reset the code but the check engine light with the same code is on all the time.

ATS Adviser:

Although you replaced all those parts, you did not indicate if those parts are from Ford which makes a lot of difference. Sometimes when you use 'aftermarket" parts, the quality might not be comparable. Also, when you said you blew the passages of the egr system with air, did you remove the throttle body? The carbon build up inside the intake manifold ports is very difficult to remove unless you take out the throttle body.

ATS Tip:

When the same code appears, it shows the problem is not solved like restricted flow.

Thursday, November 16, 2006

1997 Intrepid wiper motor won't stop even with key off: No codes




Question:

The windshield wiper motor will not stop until the fuse is taken off. I am scratching my head here because I thought replacing the wiper motor would fix it but to my surprise, it did not change anything. Suggestions?

ATS Adviser:

Symptom such as yours could be fixed by replacing the wiper motor because of a bad park switch located inside the wiper motor. However, a lot of this problem is also caused by a bad ground at the wiper motor housing and you can correct that by running a ground wire direct from the battery negative to the wiper motor housing. Assuming that won't fix it, replace the multi-function switch at your steering wheel.

ATS tips:

To verify the integrity of the wiper components, ATS can supply you the complete wiper motor wiring diagram so you can test the circuit.

Wednesday, November 15, 2006

2000 Grand Prix with 3.8L engine intermittently quits after driving for 5 miles: No codes




Question:

This car quits after being driven for 5 miles. It starts right away when re-started but I am puzzled because there is no code when scanned. I cannot check the spark or fuel signal because this happens quickly and there is no changed even after I changed the ignition module. Please help.

ATS Adviser:

Most of the symptoms you gave points to a defective crank sensor. It is located behind the front crank pulley which must be removed to access the crank sensor. Before doing it, make sure all the wiring connections to the sensor is not shorted. After replacement, reset the code and take it for a road test to confirm the fix.

ATS tip:

If after the sensor is replaced and problem re-occur, you need to check the ecm (computer) wiring terminal integrity of the ground and reference voltage signals so we can check that too.

2000 Grand Prix with 3.8L engine intermittently quits after driving for 5 miles: No codes




Question:

This car quits after being driven for 5 miles. It starts right away when re-started but I am puzzled because there is no code when scanned. I cannot check the spark or fuel signal because this happens quickly and there is no changed even after I changed the ignition module. Please help.

ATS Adviser:

Most of the symptoms you gave points to a defective crank sensor. It is located behind the front crank pulley which must be removed to access the crank sensor. Before doing it, make sure all the wiring connections to the sensor is not shorted. After replacement, reset the code and take it for a road test to confirm the fix.

ATS tip:

If after the sensor is replaced and problem re-occur, you need to check the ecm (computer) wiring terminal integrity of the ground and reference voltage signals so we can check that too.

Tuesday, November 14, 2006

1996 Ford Taurus ps pump shooting oil as soon as the car is started: No codes




Question:

My sister's 1996 Ford Taurus has a weird problem: the power steering pump shoots oil as soon as the engine is started. We installed a new power steering pump and the same thing happened. How do you fix this?

ATS Adviser:

This car's steering system uses a rack and pinion and most likely, it is shot and not allowing the oil to pass through. When that happens, oil pressure builds up in the ps pump and is forced to release it on the pump itself. This is what you are seeing during the release. To fix, replace your rack and pinion.

ATS Tip:

Make sure to flush the entire steering system after the rack and pinion is replaced.

Monday, November 13, 2006

Code 44 on 94 GM Safari with 4.3L VORTEC engine




Question:

The last few days, I am getting poor acceleration on this engine. When I scanned the codes, I got code 44 -lean exhaust. I have done a quick tune up consisting of spark plugs and wires including the fuel filter. I also changed the oxygen sensor and all of these did not seem to help. It used to bog down once a week and now it is doing it every other day. What do I do? (Note: I also tested the fuel pressure and it was 56 psi at idle).

ATS Adviser:

The give away for the fix of this problem is the fuel pressure. Any vortex engine, the fuel pressure reading is critical. It should not go down below 60 psi or you will have this symptom. Your reading is low and you need to replace the spider injector located under your engine plenum. About 90% of the time, replacing the injector (see picture) will fix this problem. If not, check the magnet of your distributor shaft.

ATS Tip:

ATS can supply you the step by step procedure in replacing the centralized spider injector if you are a member.

Thursday, November 09, 2006

1994 Ford Ranger Engine surges when AC defogger is tuned on: No Codes




Question:

My engine runs OK as long as I don't use the front dash defogger. If I set the AC button to floor setting, again engine runs fine. I scanned for codes and there is none. Can you give your insights on this problem?

ATS Advisor:

When you set your AC button to the defogger mode (see picture), the AC is actually activated and is controlled by Freon pressure which is monitored by your AC computer. When this happens, the AC computer signals the engine computer to raise the rpm to prevent the engine from stalling. However, if Freon pressure is low, the AC clutch is de-activated which cause the AC system to stop and rpm goes down. With these two modes, it will create a high or low rpm or surging condition. Try testing your Freon level and top it up with freon if possible.

ATS Tip:

Putting your AC setting to the floor mode de-activates the AC system causing your engine to run normal because the AC computer is not controlling the engine rpm anymore. ATS can supply you the Freon pressure specs for this vehicle.

Monday, November 06, 2006

Code 35 erratic engine idle for 1993 Pontiac Grand Am with 2.3L engine




Question:

My wife's Grand Am has a rough idle and it has code 35 when scanned. As per ATS info, most of this problem is solved by fixing a vacuum leaks.Is there a quick way to do this?

ATS Adviser:

Most vacuum leak can be found by runnning the engine at idle and using a propane bottle (use for soldering cooper tubings), by feeding raw propane gas on all vacuum lines and intake manifold gaskets. If you hit the vacuum leak, the engine rpm will usually change indicating a vacuum leak. Some mechanics use carburator cleaner spray can in place of the propane but can pose a fire hazard when sprayed on exhaust. To be safe, you can also spray mist of water from a spray bottle for the same effect. On most 1994 Grand Am 4 cylinder engines, the engine leak can be found on the corner of the intake manifold.

ATS Tip:

After finding and repairing the vacuum leak, reset the code to confirm the fix.

Sunday, November 05, 2006

1993 Cavalier 2.2L stalls at stop lights but will re-start in 15 minutes: No codes



Question:

My daughters car is stalling at stop lights and if she waited for 15 minutes, it
would start again. I changed the spark plugs and fuel filter and the stalling
still happens. I scanned for codes and there is none. How do I fix this?

ATS Adviser:

If you have to wait for 15 minutes before it starts, always check for spark at your plugs. If none, the problem is usually your ignition parts. Crank sensor would be the first choice even if it tested OK. You can check that by hooking a test light from your battery positive and tap the purple white wire at your ignition module connection (do this with key off). If the injectors start clicking when you touch the injectors, the crank sensor is defective and the module is OK. Otherwise, replace both module and the ignition coil.

ATS Tips:

If no starts occurs after warmed up but re-starts right away and dies again after you put it in gear, the tcc sensor is defective. you can unplug it from the side of your trany and road test again. If symptoms stop, then it is definitely a tcc sensor problem.You can leave it unplugged but you might loose some fuel mileage.

ATS can supply you the ignition wiring diagram so you can trace all the wires and location of the ignition parts.

Wednesday, November 01, 2006

P0506 IAC code on Ford F150 with 4.6L engine.




Question:

My F150 pick up truck has a bad rough idle and would surge/stall at times. After scanning, I got a code P0506- Idle air control system rpm fault problem. Does this mean I have to change the IAC motor?

ATS Advisor:

As per wiring diagram, there is no IAC motor for this engine and I suspect you have an error code. You can try resetting the computer by disconnecting the battery negative terminal or using your scanner. For your rough idle, I would try testing for vacuum leak by using a smoke machine recommended by ATS. The rpm on this is controlled by the electronic throttle control motor located in the throttle body with the help of the electronic throttle control module located in the accelerator pedal bracket. However, since there is no code on these TP sensor and module, I would try cleaning first the TB plates with intake spray and then blow it dry with air. The throttle plates are known to build up carbon deposits and causing rpm problem.

ATS Tip:

There is an extended warranty for emission on this engine and you should contact Ford to verify it.

Tuesday, October 31, 2006

Intermittent NO start and no scanner communication for 2002 Chevy Blazer 4.3L with no engine codes




Question:

What can cause my scanner not to communicate with my engine computer during no start. When this intermittent no start happens, the shift PRNDL indicator will also quit together with the dash lights. As per your blog, we changed the bcm module but the problem remains.

ATS Adviser:

That bcm will not apply here because the symptoms are entirely different,your symptoms: no start + no scanner communication + no PRNDL signal means a defective ignition switch. During no start, go to your steering column and check the yellow wire at the ignition switch below the steering wheel. If there is no power (12 volts) at the wire, the ignition switch is defective.

ATS Tips:

The ignition switch can be replaced without removing the steering wheel. Use ATS wiring diagram as a guide when locating components.

Monday, October 30, 2006

Windshield washer keeps freezing on 2002 Ford WindStar: No engine codes



Question:

How do you keep the windshield washer fluid from not freezing in the windshield? I have to stop my minivan every 20 minutes to clear the blades of ice and it is very frustrating. Help!

ATS Advisor:

Here in Canada, we use a winter anti-freeze windshield washer fluid which does not freeze in your blades. This fluid should be available in most local automotive parts store. Also, replace your windshield washer blades with winter type blades which are coated with rubber and helps prevent the blades in forming ice between the blades and the windshield. Finally, make sure your windshield defroster is turn on to heat up your windshield while your engine is running.

ATS Tip:

The air vents to your windshield defroster must a good flow. Any restriction will prevent heated air from going to the windshield. For proper servicing of the windshield washer system, contact ATS.

Sunday, October 29, 2006

P1695 no communication code for 1997 Dodge Caravan with 3.3L engine.



Question:

My check engine light is on and my dash gages are not working. The ABS light is also on and when I scanned the codes, this is what I got: P1695 no communication for CCD bus lines. How do I check this?

ATS Adviser:

If you read my previous posts about BCM, you can measure the bus line voltages of your BCM terminal pins. With key on, you should get 2.5 volts. Higher voltage could mean a short somewhere in the BCM or in other modules connected to it. You can test it by watching the voltage of the ccd bus lines and disconnecting the other module one at a time. Example: let's say you have a reading of 5 volts which is higher than our requirement. Assuming you have a few modules like AC heater control, instrument cluster, radio, ABS, Air bag, trany control and pcm. If you disconnect this one at the time and the ccd bus voltage returns to 2.5 volts, the last module that you touched is the culprit.

ATS Tip:

The most common module to go on this case is the instrument panel attributed to poor solder connections at the terminal. Take a closer look and inspect the solder and repair if necessary.

ATS will provide a wiring diagram for the above modules upon request.

P1695 no communication for 1997 Dodge Caravan with 3.3L engine.

Question:

My check engine light is on and my dash gages are not working. The ABS light is also on and when I scanned the codes, this is what I got: P1695 no communication for CCD bus lines. How do I check this?

ATS Adviser:

If you read my previous posts about BCM, you can measure the bus line voltages of your BCM terminal pins. With key on, you should get 2.5 volts. Higher voltage could mean a short somewhere in the BCM or in other modules connected to it. You can test it by watching the voltage of the ccd bus lines and disconnecting the other module one at a time. Example: let's say you have a reading of 5 volts which is higher than our requirement. Assuming you have a few modules like AC heater control, instrument cluster, radio, ABS, Air bag, trany control and pcm. If you disconnect this one at the time and the ccd bus voltage returns to 2.5 volts, the last module that you touched is the culprit.

ATS Tip:

The most common module to go on this case is the instrument panel attributed to poor solder connections at the terminal. Take a closer look and inspect the solder and repair if necessary.

ATS will provide a wiring diagram for the above modules upon request.

P1695 no communication for 1997 Dodge Caravan with 3.3L engine.

Question:

My check engine light is on and my dash gages are not working. The ABS light is also on and when I scanned the codes, this is what I got: P1695 no communication for CCD bus lines. How do I check this?

ATS Adviser:

If you read my previous posts about BCM, you can measure the bus line voltages of your BCM terminal pins. With key on, you should get 2.5 volts. Higher voltage could mean a short somewhere in the BCM or in other modules connected to it. You can test it by watching the voltage of the ccd bus lines and disconnecting the other module one at a time. Example: let's say you have a reading of 5 volts which is higher than our requirement. Assuming you have a few modules like AC heater control, instrument cluster, radio, ABS, Air bag, trany control and pcm. If you disconnect this one at the time and the ccd bus voltage returns to 2.5 volts, the last module that you touched is the culprit.

ATS Tip:

The most common module to go on this case is the instrument panel attributed to poor solder connections at the terminal. Take a closer look and inspect the solder and repair if necessary.

ATS will provide a wiring diagram for the above modules upon request.

P1695 no communication code for 1997 Dodge Caravan with 3.3L engine.

Question:

My check engine light is on and my dash gages are not working. The ABS light is also on and when I scanned the codes, this is what I got: P1695 no communication for CCD bus lines. How do I check this?

ATS Adviser:

If you read my previous posts about BCM, you can measure the bus line voltages of your BCM terminal pins. With key on, you should get 2.5 volts. Higher voltage could mean a short somewhere in the BCM or in other modules connected to it. You can test it by watching the voltage of the ccd bus lines and disconnecting the other module one at a time. Example: let's say you have a reading of 5 volts which is higher than our requirement. Assuming you have a few modules like AC heater control, instrument cluster, radio, ABS, Air bag, trany control and pcm. If you disconnect this one at the time and the ccd bus voltage returns to 2.5 volts, the last module that you touched is the culprit.

ATS Tip:

The most common module to go on this case is the instrument panel attributed to poor solder connections at the terminal. Take a closer look and inspect the solder and repair if necessary.

ATS will provide a wiring diagram for the above modules upon request.

P1695 no communication code for 1997 Dodge Caravan with 3.3L engine.

Question:

My check engine light is on and my dash gages are not working. The ABS light is also on and when I scanned the codes, this is what I got: P1695 no communication for CCD bus lines. How do I check this?

ATS Adviser:

If you read my previous posts about BCM, you can measure the bus line voltages of your BCM terminal pins. With key on, you should get 2.5 volts. Higher voltage could mean a short somewhere in the BCM or in other modules connected to it. You can test it by watching the voltage of the ccd bus lines and disconnecting the other module one at a time. Example: let's say you have a reading of 5 volts which is higher than our requirement. Assuming you have a few modules like AC heater control, instrument cluster, radio, ABS, Air bag, trany control and pcm. If you disconnect this one at the time and the ccd bus voltage returns to 2.5 volts, the last module that you touched is the culprit.

ATS Tip:

The most common module to go on this case is the instrument panel attributed to poor solder connections at the terminal. Take a closer look and inspect the solder and repair if necessary.

ATS will provide a wiring diagram for the above modules upon request.

P1695 no communication code for 1997 Dodge Caravan with 3.3L engine.

Question:

My check engine light is on and my dash gages are not working. The ABS light is also on and when I scanned the codes, this is what I got: P1695 no communication for CCD bus lines. How do I check this?

ATS Adviser:

If you read my previous posts about BCM, you can measure the bus line voltages of your BCM terminal pins. With key on, you should get 2.5 volts. Higher voltage could mean a short somewhere in the BCM or in other modules connected to it. You can test it by watching the voltage of the ccd bus lines and disconnecting the other module one at a time. Example: let's say you have a reading of 5 volts which is higher than our requirement. Assuming you have a few modules like AC heater control, instrument cluster, radio, ABS, Air bag, trany control and pcm. If you disconnect this one at the time and the ccd bus voltage returns to 2.5 volts, the last module that you touched is the culprit.

ATS Tip:

The most common module to go on this case is the instrument panel attributed to poor solder connections at the terminal. Take a closer look and inspect the solder and repair if necessary.

ATS will provide a wiring diagram for the above modules upon request.

Wednesday, October 25, 2006

P0121 tps sensor code for 2001 Ford Focus with 2.0L engine.




Question:


My sister's 2001 Ford Focus check engine light is on and it is hesitating. After scanning for codes, I got P0121 which is a faulty tps sensor. I am new to this ATS but I have a digital voltmeter, can you send me the procedure in testing this code?

ATS Advisor:

On this tps sensor, you have 3 wires. On one end is the ground wire and the other end is the reference voltage wire. The middle wire is your tps signal voltage. Check out the ground wire and reference voltage wire at the sensor itself. The ground voltage should give you 0.250 volt or less with key on. If reading is higher, you have a shorted wire in your ground wires or the tps sensor. The reference voltage is almost always fixed at 5 volts. Finally, the signal wire is best checked at ecm (computer) terminal pin. With engine at idle, expect to get 0.5 to 1.2 volts. At high idle, the reading goes up to roughly 4.5 to 5.0 volts.
If you are not getting these readings, repair the wires or replace the tps sensor.

ATS Tip:

When you get the ATS wiring diagram, the ecm pin wire color and designation will be shown to you.

Tuesday, October 24, 2006

P0340 camshaft sensor code for 1996 Ford Taurus with 3.8L engine




Question:

My car is hesitating and came with this code P0340 which is a camshaft sensor fault and my mechanic replaced it including the synchronizer that goes with the camshaft sensor. However, the check engine light stayed with the same code and the hesitation is still there. I am not sure if we did this job properly or we bought a defective sensor. Please advice.

ATS Advisor:

First of all, this code is not caused by defective camshaft sensor alone. It can be triggered by a fault in the egr system especially the DPFE sensor which emits electrical interference and interfere with the electrical signal resulting in this code. A quick way to check it is to remove the vacuum hose going to the egr valve port and take the vehicle for a road test. If hesitation stops, it is a definite sign that the DPFE sensor is defective (make sure to plug the vacuum hose during road test).

ATS Tip:

Please read previous blog post about Ford dpfe sensor so you can locate it. You can search this blog by typing "dpfe sensor" on the top left search bar and click "search this blog".

Monday, October 23, 2006

Dash panel lights are coming on and off while driving for 2000 Grand Voyager: No codes




Question:

My dash panel is driving me crazy because it would come on and off while I am driving. Also, the windshield wipers will not shut down when I used them and my power doors are acting funny by not unlocking. Finally, the blower heated motor will only work in high speed. Is this a body control module (bcm) problem?

ATS Advisor:

Yes you are correct, the bcm is going and you can check that by resetting it first by disconnecting your battery negative terminal for a few minutes and reconnect. then see if the symptoms return to confirm. If it does, check all the ground wires of the bcm as per wiring diagrams that I will send you. If no shorted wire is found, replace the bcm from the dealer. They will usually re-program it for you based on your vehicle's serial number.

ATS Tips:

Please read all previous postings on this blog about bcm.
The mileage of your dash panel is stored in your bcm which should be installed when the new one is programmed.
The blower motor needs a new resistor so it will work on all speeds.

Thursday, October 19, 2006

Engine no start with check engine light for 2002 GM Silverado with 5.3L engine



Question:

This truck will not start despite the fact that it has spark and injector signal. I also replaced the maf sensor and the engine compression reading for all cylinders are normal. When I scanned for codes, there are numerous codes that lead me to think that I have a computer problem.

ATS Advisor:

When you get numerous codes stored in your computer and there is spark and injector signal at the same time, this is an indication of a defective computer. However, you can actually test it by tapping the computer and wiggling the computer wiring harness to see if it would start. Remember also to drop the exhaust manifold in case the exhaust converter is plugged inside. Finally, you can check the ground and reference voltage wires of the computer terminals to see if they are within limits. If all of these fail to start the engine, replace the computer.

ATS Tip:

Before replacing the computer, contact ATS in case there is a service bulletin involved regarding the computer failure which might be under recall or warranty.

Wednesday, October 18, 2006

Using wiring diagram to fix the check engine light codes in your dash panel

Click this link for the image!

Question:

I have this check engine light in my dash and have a code for it. My problem is I don't know how to use the wiring diagram in order to fix it. I am not a mechanic and could use your help if you can explain how to use the wiring diagram.

ATS Advisor:

Shown in the "LINK" above is a typical wiring diagram that we sent to ATS customers if they need a wiring diagram. As you can see, the path of the power and ground circuits are highlighted so you can understand how the system is working. As a member of ATS, we will explain to you the proper test and use of the wiring diagram. Once you tried it, you will know how simple it is. This way, you are not on your own trying to analyze it because it is already done for you.

ATS Tip:

Try searching this blog by typing the word "wiring diagram" in the above blogger search box (top left corner) and click "search this blog" and you will know everything about wiring diagram.

Tuesday, October 17, 2006

P0121 TPS sensor code for 1997 Honda Accord with 2.2L engine




Question:

My vehicle is running fine but my check engine light would come on intermittently once in a while. When I scanned for codes, it was P0121 -TPS sensor "A" circuit range/performance. So I put a new sensor but the light came back after I road test the car and got the same code. Does this means I have to change the engine computer too?

ATS Adviser:

If the car is running OK, I would say your problem is probably the wiring to your TPS sensor. Since it is intermittent, what is probably happening is there is a shorted wire that would touch something while you are driving that would trigger this. To check, try probing all the wires to the tps sensor and while reading the voltage, try wiggling the wires and see if there is a change in the reading (do this with key on). If the reading changes, then you found your culprit wire.

ATS Tip:

You need a wiring diagram to do this so you can identify all the wiring colors of the tps sensor (please contact ATS).

Monday, October 16, 2006

P0121 and P0112 codes for 1999 Chrysler Sebring with 2.5L engine




Question:

My car is running rough and stalls at stop lights. When I scanned for codes, I got P0121-Throttle/Pedal position sensor A circuit range/performance and P0112-Intake air temperature sensor 1 circuit low (bank 1). I checked for vacuum leak as per ATS lessons but I could not find any. Where do I start?

ATS Advisor:

Try fixing the first code first (P0121) and then reset it after you have done the repair. To check this code, measure the voltages of the TPS signal wire and if not within range, replace it. A lot of times, this sensor will fail because of its proximity with the egr valve which could be the source of the problem especially if stuck open. When it does, it will also trigger the second code. Test the egr valve by touching the egr tube if it is abnormally hot. If it is, then replace both egr valve and tps sensor.

ATS Tip:

If egr is stuck open, it will cause your air temperature to get higher.
Make sure the tps sensor ground wire does not exceed 0.250 volt.

Sunday, October 15, 2006

No Start problem for 2000 Ford WindStar with 3.8L engine: No Codes




Question:

My minivan quit on me yesterday and I did a quick tune up changing the spark plugs and wires including air and fuel filters and it would not start. I checked for the injector signals and they were blinking OK. My fuel pressure when tested was within limits (30-45 psi) but when I checked for spark, there is none. So I replaced the ignition module but still it won't start. My only choice left is either the ignition coil or the engine computer. How do I check it?

ATS Adviser:

You can check the ignition coil (called coil pack) by 2 methods. First, measure the resistance between the pcm terminal ignition pins 26, 52 and 78 against the coil pack pins CD-1, CD-2 and CD-3. You should get 5 ohms or less. Second, measure the resistance between ignition coil towers and you should get between 10,000-14,500 ohms. If your reading is not within this range, replace the ignition coil. The PCM is tested by measuring the ground and reference voltages as shown earlier in other blogs.

ATS Tip:

When testing the ignition coil, disconnect the inertial switch to disable the fuel pump. If you need a wiring diagram to guide you, please contact ATS.

Saturday, October 14, 2006

P0441 Emission Code for 1999 Toyota Camry with 2.2L engine



Question:

My check engine light is on and I got this code P0441 Evaporative System Incorrect Purge Flow after I scanned it. I checked the fuel tank cap and it was good. Where do I start?

ATS Adviser:

The most common cause of this code comes from the failure of the VSV sensor by the Charcoal Canister. What happens is the canister itself begins to break inside and creates a lot of debris which can penetrate the VSV sensor passages. When this happens, it will disrupt the sensor setting when the sensor closes or opens triggering the code. This is very common on this model and you are better off replacing the charcoal canister assembly. The canister comes complete with new sensors but you need to blow the lines to remove the unwanted charcoal particles inside.

ATS Tip:

To save money, you can remove the VSV sensor so you can open it up and clean of debris. However, the code will repeat again unless you replace the charcoal canister.

Friday, October 13, 2006

Starter not working intermittently for 1998 Toyota 4Runner: No codes



Question:

These last few days my starter does not work all the time. When I first started it, all I hear is the clicking sound. After a few attempts on the ignition key, it would start and be OK the rest of the day. My battery is new and I am thinking of replacing the starter but it is expensive and I want to know if I have a cheaper alternative?

ATS Advisor:

As a matter of fact, you have a cheaper choice in repairing your starter. Most of this problem comes from worn solenoid contacts inside the starter. Instead of buying the whole starter assembly, you can buy the contact from Toyota or any electrical automotive parts store. It cost roughly under $20 and you might even get away of not removing the old starter. The labor flat rate for this is approximately 3 hours and you should be able to this in one weekend without breaking a sweat.

ATS Tip:

For wiring diagram for the starting circuit including the complete details in fixing your starter contacts, please email ATS.

Thursday, October 12, 2006

Alternator won't charge for 1999 Chevy Camaro with 3.8 L engine: No engine codes




Question:

My battery was going dead on me and when I checked my battery voltage at idle, it was discharging. After cleaning all the grounds and having the same result, I replaced the alternator with a rebuilt one from a local parts store. However, my battery light is still on and when I checked it, it was still discharging. I thought the rebuilt alternator was defective so I returned it and got a 2nd one installed but I got the same result. What have I done wrong?

ATS Advisor:

Some aftermarket alternator available has a regulator with 12 volts triggering signal to make it work. If you buy one from GM dealer, the triggering voltage comes from the engine computer (ecm) and only supplies 5 volt. I think this is your problem. Try using an AC Delco alternator from the dealer and you should be fine.

ATS Tip:

If you want a wiring diagram for this charging system, please contact ATS.

Wednesday, October 11, 2006

P0171 and P0174 lean mixture codes for 1999 Ford WindStar with 3.8L engine




Question:

My dash panel light is always on for about a week and when I scanned it, 2 codes showed up: P0171 lean bank 1 and p0174 lean bank 2. I replaced both oxygen sensors and cleaned the mass air flow sensor but after resetting the codes, the light is still on? All my spark plugs were just replaced including fuel filter. Help!

ATS Advisor:

Unlike GM engines where cleaning the mass air flow sensor will give you results, on Fords you have to replace it if you get this codes. However, before doing this make sure there is no vacuum leak like the PCV hoses which are prone to cracking. To be sure, have a garage to do a smoke test on your engine to eliminate the possibility of a vacuum leak.

ATS Tip:

Every time there is a lean code, don't waste your time and change the mass air flow sensor right away if there's no vacuum leak using a vacuum gage. You should get a reading not lower than 17 inch of vacuum.

Tuesday, October 10, 2006

Wiper Motor works intermittently on 1999 Chevy Pick Up Truck: No engine codes




Question:

My Truck's wiper motor is acting up lately, it would OK and then abruptly quit working unless I manually move the blades to shake it. I can also activate it if I play around with the ignition key (shutting it off and on a few times). Finally, I thought I heard the wiper motor buzzing when it quit on me. Do I have to replace the wiper motor?

ATS Advisor:

This problem is common with this GM truck model and most of the time; the culprit is a defective wiper module. This part is found inside the wiper motor and very easy to replace. You can test it by tapping the motor when it is not working and the motor will come alive. Once you verified this, it's a matter of removing the motor assembly and changing the module inside.

ATS Tip:

If the price difference is not much, you are better off changing the whole wiper motor assembly.

Monday, October 09, 2006

Engine no start for 1994 VW Golf with 1.8L engine: No engine code




Question:

I have this car that I bought from the auction lot a month ago and would not start on me yesterday. There is no spark but I have an injector signal when I tested it with a noid light tester as per ATS. I also checked the battery side of the coil and but the tach side would not blink. Reading your articles, I now suspect the ignition module is bad but how to I check it?

ATS Advisor:

Your spark is controlled by your ignition module which connects to the fuel pump relay. Have a look at the relay if it is clicking with your fingers when you turn the key on. If bad, that relay can ground the tach signal and will cause no spark. Also, make sure there is continuity between the ecu (computer) pin 6 and the module pin 2. Finally, check the ignition module ground near the battery for corrosion and loose connection. If all of these checks OK, replace the ignition module.

ATS Tip:

Use ATS wiring diagram to trace ignition module wiring connections.