DTC P0123 - Throttle Position (TP) Sensor Circuit High Input
- Disconnect TP sensor harness connector. Turn ignition on. Using a voltmeter, measure voltage between Gray/Red wire and Gray/Yellow wire of TP sensor harness connector. If reading is 4-5 volts, go to next step. If reading is not as specified, check Gray/Yellow wire for an open or poor connection. Check Gray/Red wire for a short to power. Repair as necessary. Retest system.
- Turn ignition off. Reconnect TP sensor harness connector. Turn ignition on. Measure voltage between PCM harness connector "B", terminal No. 17 and ground while moving throttle from idle to fully open position. If reading is .35-.65 volt at idle position and 3.5-4.5 volts with throttle fully open, check for poor connection at PCM. If connections are okay, replace PCM. If reading is a constant 4-5 volts, check for open in Gray/Yellow wire, Gray wire shorted to Green/Red wire or poor connection at TP sensor. Repair as necessary. If reading is other than described, adjust or replace TP sensor. Retest system.