DTC P0123 - Throttle Position (TP) Circuit High Input

Connect scan tool to Data Link Connector (DLC). Turn ignition on. Observe throttle valve opening percentage on scan tool while slowly opening throttle valve to fully open position. If display increase to 96 percent or greater, go to next step. If display reading is less than 96 percent, check for an intermittent problem. See the TESTS W/O CODES article.
Turn ignition off. Disconnect harness connector from TP sensor. Turn ignition on. Using a voltmeter, measure voltage between ground and Pink wire at TP sensor harness connector. If reading is 4-6 volts, go to next step. If reading is greater than 4-6 volts, repair Pink wire for short to battery power. Retest system.
Turn ignition off. Unplug PCM connector "B". Using an ohmmeter, check for continuity between Green/Red wire at TP sensor harness connector and PCM harness connector "B", terminal No. 9. If continuity exists, go to next step. If continuity does not exist, check Green/Red wire for an open or poor connection. Repair as necessary. Retest system.
Reconnect PCM connector. Turn ignition on. Using a voltmeter, measure voltage between ground and Gray wire at TP sensor harness connector. If reading is zero volts, go to next step. If reading is 4-6 volts, repair Gray wire for short to Pink wire. If reading is battery voltage, repair Gray wire for short to power. Repair as necessary. Retest system.
Using an ohmmeter, measure resistance between the specified TP sensor terminals. Refer to the TP SENSOR RESISTANCE table. See Figure . Replace TP sensor if resistance is not as specified. If resistance is as specified, replace PCM. Retest system.