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.

Sunday, October 08, 2006

Multiple engine light codes and engine hesitates, cutting outs for 1997 Camaro with 5.7L engine



Question:

My engine is hesitating and cutting out with check engine light on. Got codes for oxygen and egr which were both replaced. Despite these, the engine kept having poor pick up and stalls. I am thought cleaning the MAF sensor would fix this problem but no change either. I am at a loss and contemplating to replace the engine computer (ecm). Please help.

ATS Advisor:

If I am not mistaken, this engine came with both MAP and MAF (mass air flow) sensors and although you cleaned the MAF sensor, you may not have it tested properly. A quick way to do it is to unplug the MAF sensor and see if the problem stops. If it does, replace the MAF sensor.

ATS Tips:

When you disconnect the MAF sensor, all the loads of the engine is calculated by the ecm using the MAP signal and MAF readings will be set at default instead of the actual MAF signal.

Another indicator of a bad MAF sensor is dirt built up in the air filter which contaminates the MAF sensor wiring elements. When in doubt, replace the MAF sensor if you see a dirty air filter.

Saturday, October 07, 2006

P0336 crank sensor code for 1998 Honda Civic with 1.6L engine



Question:

I just bought a Honda Civic from a used car lot a month ago. Yesterday, it was cutting out and a check engine light was on. When scanned for codes, I got P0336 which is crank sensor fault. The engine also has a misfire intermittently during acceleration. Reading your blog, it seems the distributor is the culprit. However, it is very expensive from the dealer and I am not sure if the ones available from my local parts store are good enough. Suggestions?

ATS Advisor:

If you have this code P0336, the distributor is definitely toast but buying an aftermarket distributor is a bad choice. If you like, instead of buying a complete distributor assembly from the dealer, you can buy the distributor housing only. It comes with all the pick up sensors and you can use the original coil and igniter from your old distributor.

ATS Tip:

Always reset the code after performing the repairs. For details on how to overhaul the distributor, please contact ATS.

Friday, October 06, 2006

P0031 Oxygen sensor code for 2000 Dodge Ram with 5.9L engine.




Question:

One of my injectors has a bad PCM driver after using the noid light tester that you recommended. I replaced it including the injector wiring harness (it was shorting out which was the original cause of the injector failure). After I replaced the PCM bought from the dealer, the misfire was gone and the engine ran good. However, my mill light was still on and has a code P0031 which was not there before. Did I get the right type of PCM from the dealer? How do I check it?

ATS Advisor:

When you buy your PCM from the dealer, they usually programmed the PCM based on your vehicle's serial number. If it is, try using the wiring diagrams and actually check the colors of the wires indicated in the PCM terminals. I have seen in some other cases where an older model was the right PCM...example: a 1999 PCM was used instead of a 2000 PCM was used on the vehicle. And you can check that by comparing the wiring colors shown in the diagram. Try this and let me know.


ATS Tip:

Before doing the above test, try calling your dealer to supply you with another PCM. The new one that you have might be defective and this happens sometimes.

Thursday, October 05, 2006

P1716 No communication with PCM for 1998 Chrysler Town & Country with 3.8L engine

Question:

My car has a mill light coming on and when I scanned it, I got an error code: P1716 which is not listed in obd2 codes (error code). The engine runs great but the light bothers me and I cannot check the data for my engine. Any suggestions?

ATS Advisor:

First of all, try checking the integrity of your scanner by trying a second scanner and see if you can get the same error code. The best scanner to use on this is the "BRICK" or the MT2500 Snap-On scanner which is very popular with small garages. For a small fee, any garage could do this for you unless your parts store has this type of scanner. If the same code appears, here are some common causes of this problem: Poor power and ground connections at the PCM or at the data link connector (DLC), defective instrument panel connections, bad wiring harness or defective PCM itself.

ATS Tips:

Specific testing of the PCM and other modules such as the TCM (trany control module), BCM and other accessories can be sent to you once you confirmed the code.

Measure the CCD Bus voltages at PCM pins 59 and 60 with key on, you should get 2.25 volts, if higher than this, the PCM might be defective.

Wednesday, October 04, 2006

No start on 1995 Honda Accord with 2.2L engine: No engine code




Question:

I have no start on this car and when I checked it, I had fuel at the injectors but has no spark. I suspect my distributor is bad but it is expensive, how do I check it?

ATS Advisor:

If you check your distributor wires, check the yellow green wire. This wire comes from your distributor module called igniter. With key on, there must be 9 volts reading on it. The way it works, the module sends this signal voltage to the engine computer (ecm) and then the computer sends ground to the igniter to fire the coil. You can actually do this manually: Turn key on, disconnect the yellow green wire and briefly touch the igniter with a jumper wire from a ground connection. You should see a spark generated at the coil.

ATS Tips:

If you have less than 7 volts in the igniter, the ecm will likely not send ground to it. (bad igniter or poor ground connection).

Make sure the connection between igniter and ecm is not open (broken)

Bad spark plugs and wires usually take out the igniter.

If you can afford it, replace the ignition coil also.

Tuesday, October 03, 2006

Dash panel lights quit on 1999 Dodge Caravan with 3.3L engine: Scanner won't




Question:

My dash panel lights that include tachometer, speedo, fuel, temperature and trany indicator just quit the other day. Last night, while driving home, I noticed the same dash panel lights flickering on and off when I turned on the headlights. There is no performance problem on the engine and it ran fine. However, when I scanned the codes today, the scanner just showed blank and not communicating with the engine computer. How do I fix this without going to the garage?

ATS Advisor:

Your instrument panel is controlled by your body control module (BCM) located under the dash on the left side of your steering column on top of the brake pedal. But a good way to check the BCM is to unplug it and see if the scanner now communicates with your engine computer (PCM) located on the left corner/fender of the engine compartment. If the BCM is defective, your scanner should come alive and function normally. Also in the BCM, you can measure the "ccd bus" voltage using ATS wiring diagram and specs so you can test for abnormal reading on its terminal pins. Finally, the dash panel unit can be taken out and checked for proper connections especially the soldered pins which can cracked and cause this problem.

ATS Tip:

If you are replacing the BCM, give the dealer the serial number of the vehicle and the mileage so they can program it on the new BCM.

Monday, October 02, 2006

Battery goes dead after parked overnight for 2000 Ford Taurus with 3.0L engine

Question:

My battery goes dead after my vehicle is parked overnight. The charging rate for the alternator is good and the battery was just replaced. If I test the battery drain, it is within limits. Also, my dome lights won't work but all the fuses are OK. Some friends say that there is a battery saver for this car, how do you check it?

ATS Advisor:

Your battery saver works together with your body control module called "GEM" module. This module is active all the time and needs 45 minutes to be on (or sleep) after you shut the key off. If any of the body functions like lights, accessories, door opening are shorted, the module will be on all the time causing the drain. To check, wait for 45 minutes before testing for drain. If drain is present, get the codes for the GEM module and fix it. Your dome lights circuit should be corrected first since this can get your GEM module to be active all the time.

ATS Tip:

You need a wiring diagram for the GEM module and interior lights which can be requested from ATS if you are a member.

Sunday, October 01, 2006

P0304 Code misfires on cylinder for 1999 S10 Truck with 4.3L engine

Question:

My truck has a pronounced miss on idle but goes away when I rev it up. When I scanned for codes, #4 cylinder is missing. I tried relocating the spark plugs and wires of this cylinder but the code remained the same (miss at #4 cylinder). I suspect this problem is mechanical but can you guide me?

ATS Advisor:

One of the quickest ways to find if your #4 cylinder is OK is to take a compression test on all cylinders and compare it with #4. You can also hook up a vacuum gage and watch it while your engine is idling. If the needle of the vacuum gage is fluctuating and not steady, that is a sure sign of cylinder valve failure. Finally, you can measure the resistance of each injector and compare them also.

ATS Tip:

If you confirm from above that your problem is mechanical, take out the engine valve cover so you can inspect the rockers and valve train.