What does Error Code P0123 mean?
Critical 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 are the symptoms of 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 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.
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How to fix 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 Check: If all previous steps are normal, inspect the Engine Control Unit (ECU) for any faults or issues that might be causing incorrect readings.