Throttle Position Sensor: Testing and Inspection

NOTE: Before testing the TPS, the throttle linkage must be checked for correct adjustment. The throttle lever must do the following:

^ Contact the low idle speed screw
^ Reach breakover when the throttle is wide open

If the throttle lever does not meet both of the previous conditions, adjust the throttle linkage.
The Throttle Position Sensor (TPS) can be tested with a digital voltmeter. The center terminal of the TPS electrical connector is the output terminal.

Throttle Position Sensor:

1. Using a sharpened paper clip, back probe the center electrical terminal of the TPS electrical connector.
2. Rotate the ignition switch to the ON position, and check the voltage reading at the TPS output terminal.
3. Check the voltage level when the TPS is in the idle position. The voltage should be approximately 1 volt.
4. Check the voltage level when the TPS is in the wide open throttle position. The voltmeter should read approximately 3.25 volts.
5. The voltage readings on the voltmeter should increase smoothly as the throttle position is changed from idle to wide open throttle.
6. If the TPS voltages are not within range, then the TPS needs adjustment.
7. If the voltmeter gets erratic voltage readings when the TPS is rotated from idle to wide open throttle, then replace the TPS as a unit.