Throttle Position Sensor: Testing and Inspection

NOTE: The following procedure tests the TPS only. To perform a complete test of the TPS and its circuitry, SEE Computers and Control Systems/Testing and Inspection/Procedures/Diagnostic Charts.

PROCEDURE
1. The TPS can be tested with a digital voltmeter. The center terminal of the TPS is the output terminal. One of the other terminals is a 5 volt supply and the remaining terminal is ground.

2. With the ignition key in the ON position, check the TPS output voltage at the center terminal wire of the connector. Check this at idle (throttle plate closed), and at Wide Open Throttle (WOT).
- At idle, TPS output voltage should be greater than 0.4 volts.
- The output voltage should increase gradually as the throttle plate is slowly opened from idle to WOT.
- At wide open throttle, TPS output should be less than 3.8 volts.

NOTE: Check for spread terminals at the sensor and PCM connections before replacing the sensor.