Throttle Position (TP) Sensor
NOTE:
Malfunctioning TP sensor may also set Code 21A or 21B. For additional testing, see TESTS W/CODES - 3.2L
article.
- Unplug TP sensor harness at sensor. Connect ohmmeter between Blue/Orange and Blue/Red wire terminals of sensor.
- Resistance reading should vary smoothly as throttle is moved from idle to wide open throttle. Resistance reading should not drop or climb suddenly as continuity is checked. Replace sensor if defective.
- To check sensor operating voltage, connect TP sensor harness. Sensor operating voltage may be monitored at ECM with ignition on. Note ECM location. See ECM LOCATION table.ECM LOCATION
Model Location Trooper Under Instrument Panel - Turn ignition on. DO NOT start engine. Using digital voltmeter, backprobe ECM connector terminals to check if 5-volt TP sensor reference signal exists. Reference signal should exist at ECM terminal A1 (Blue/Orange wire).
- If 5-volt reference signal is not present, check for short to ground in 5-volt reference line from ECM to TP sensor. If no short is present, ECM is defective.
- If 5-volt reference signal is present, test TP sensor input signal at appropriate ECM terminal. Connect negative voltmeter probe to ground. Backprobe ECM terminal with positive voltmeter probe at ECM terminal D6 (Blue/Red wire).
- With engine running, voltage should be about .5 volt at idle and increase to about 5 volts at wide open throttle. If voltage reading is incorrect, check wiring to TP sensor. If wiring is okay, replace TP sensor.