Jeep P0123 Fault Code: TPS Signal Voltage Issue and Diagnosis Steps
I'm experiencing a Jeep P0123 fault code related to the Throttle Position Sensor (TPS). After removing the TPS connector, I tested the wires and found that the signal wire (BRN/ORG) reads 4.7V at its highest — but it should only reach up to 1V according to specifications. When I cut the signal wire close to the Power Control Module (PCM), there is no power detected on the TPS plug side, although the PCM end still shows 4.7V. This suggests a possible wiring issue or internal fault in the sensor circuit. I'm not sure if this is a faulty TPS or a problem with the signal path between the sensor and the PCM. Any insight into how to properly diagnose this P0123 code on a Jeep would be greatly appreciated.
What year is your Jeep? Are there any other diagnostic trouble codes (DTCs) present? Specifically, can you confirm the voltage reading on the BRN/ORG signal wire when the TPS is unplugged and the PCM side shows 4.7V? Also, please share the exact model and engine type of your vehicle — this helps narrow down potential causes. Any additional symptoms like poor acceleration, stalling, or check engine light behavior would be helpful. Additionally, are you using an OBD2 scanner to retrieve codes, or only relying on key-on/off cycles? A proper scan tool is essential for accurate diagnosis of P0123 and related issues.