Error Code P0123
Moderate Issue
DTC Code P0123 indicates a Throttle Position Sensor/Switch 'A' Circuit High Input, where an excessively high voltage from the Throttle Position Sensor (TPS) is sent to the Engine Control Module (ECM).
What symptoms indicate Error Code P0123?
- Engine Light ON: The check engine light or service engine soon warning light illuminates, indicating a potential issue with the throttle position sensor.
- Poor Acceleration: The vehicle may experience sluggish or unresponsive acceleration due to incorrect throttle position readings.
- Erratic Idle: The engine may idle erratically or stall, as the throttle position sensor provides inaccurate data to the engine control module.
- Reduced Fuel Efficiency: Fuel consumption may increase as the engine control module struggles to maintain optimal air-fuel mixture.
What causes OBD code Error Code P0123?
- The throttle position sensor may be malfunctioning, leading to incorrect voltage signals being sent to the engine control module.
- An open or shorted throttle position sensor harness can disrupt the electrical flow, causing the sensor to send high input signals.
- Poor electrical connections in the throttle position sensor circuit can result in intermittent or incorrect signal transmission, triggering the error code.
How to fix OBD code Error Code P0123?
- Initial Inspection: Inspect the throttle position sensor (TPS) and its wiring for any visible damage or disconnection. Ensure the connectors are secure and free from corrosion.
- Check Voltage Supply: Using a multimeter, measure the voltage at the TPS connector. The reference voltage should be around 5 volts. A higher reading indicates a potential short to voltage.
- Sensor Ground Verification: Verify the ground circuit of the TPS. A poor ground can cause high input readings. Ensure continuity between the sensor ground and the engine ground.
- Signal Wire Inspection: Check the signal wire for continuity and any signs of short circuits. A short to voltage in the signal wire can cause a high input reading.
- TPS Resistance Test: Disconnect the TPS and measure its resistance. Compare the readings with manufacturer specifications to determine if the sensor is faulty.
- ECU Testing: If all previous steps are normal, test the Engine Control Unit (ECU) for faults. A malfunctioning ECU can misinterpret sensor signals.
- Related Codes Analysis: Review related DTC codes such as P0120, P0121, and P0122 to identify any patterns or additional issues that may be affecting the TPS circuit.