Tip #14: Testing TPS sensor check engine light codes

TPS or throttle position sensor monitors the movement of your throttle linkage when you step on your gas pedal. A quick way to find it is to follow the linkage rod or cable connected to your gas pedal. You will find it ends on the throttle body (TB) below the air filter housing. On the side of this TB housing is the tps sensor accompanied by 3 wire terminals: one for ground, second for 5 volt reference and the 3rd one: the signal wire.

How to check your tps sensor?

You don’t even have the engine running to check your tps sensor. Just access the middle or 3rd wire and using a voltmeter, measure the voltage against the vehicle ground. With throttle on close position (the setting where the engine runs at idle), the voltage should be around 0.5 volt. Now move the throttle linkage to full or wide open throttle position (just like flooring the gas pedal to get max fuel and speed). The reading should be from 4.5 -5 volts. If the tps sensor is not getting this range, then the sensor is bad. Remember to turn the key on when performing this test.


Shown here is an example of a tps sensor.

This applies to most kind of vehicles whether domestics or imports. If you need the exact wiring diagram for the middle (signal) wire, contact your local dealer or ATS.