P0123
DTC P0123: TP Sensor Circuit High Voltage1. Start the engine. Hold the engine at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on, then turn the ignition switch OFF.
2. Turn the ignition switch ON (II).
3. Check the throttle position with the scan tool.
Is there about 10% when the throttle is fully closed and about 90% when the throttle is fully opened?
YES - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the TP sensor and the PCM.
NO - Go to step 4.
4. Turn the ignition switch OFF.
5. Disconnect the TP sensor 3P connector.
6. Turn the ignition switch ON (II).
7. At the wire harness side, measure voltage between TP sensor 3P connector terminals No.1 and No.3.
Is there about 5 V?
YES - Replace the throttle body.
NO - Go to step 8.
8. Measure voltage between PCM connector terminals C18 and C28.
Is there about 5 V?
YES - Repair open in the wire between the PCM (C18) and the TP sensor.
NO - Substitute a known-good PCM and recheck. If voltage is normal, replace the original PCM.