Accepted Answer

You need to check and see if the TPS goes to 0 volts as the throttle closes. It may be confusing the computer and causing it to hold the idle up a little.

Here is the procedure:

1. Backprobe with a high impedance voltmeter at TPS terminals A and B.
2. With the key ON and engine off, the voltmeter reading should be approximately 5.0 volts.
3. If the voltage is not as specified, either the wiring to the TPS or the ECM may be faulty. Correct any wiring or ECM faults before continuing test.
4. Backprobe with a high impedance voltmeter at terminals C and B.
5. With the key ON and engine off and the throttle closed, the TPS voltage should be approximately 0.5-1.2 volts.
6. Verify that the TPS voltage increases or decreases smoothly as the throttle is opened or closed. Make sure to open and close the throttle very slowly in order to detect any abnormalities in the TPS voltage reading.
7. If the sensor voltage is not as specified, replace the sensor.

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Expert:	Ted G.
Pos. Feedback:	99.5 %
Accepts:
Answered:	10/23/2009

ASE Certified Technician

20 years auto repair experience, ASE Master Tech, Mechanical Failure consultant, Expert Witness