P0123 – OBD-II DTC

OBD-II DTC P0123 – Throttle Position Sensor/Switch A Circuit High Input

DTC P0123 meaning

DTC P0123 refers to a diagnostic trouble code indicating a high input signal from the Throttle Position Sensor (TPS) or switch A circuit. The TPS is responsible for monitoring the position of the throttle plate in the engine’s intake system. This information is crucial for the Engine Control Module (ECM) to manage fuel injection and ignition timing effectively. A high input signal suggests that the TPS is reporting a position that is outside the expected range, which can lead to performance issues.

DTC P0123 symptoms

Common symptoms associated with DTC P0123 may include:

• Illuminated check engine light
• Unresponsive or erratic throttle response
• Engine stalling or hesitation during acceleration
• Reduced engine power or limp mode activation
• Poor fuel economy

DTC P0123 causes

Several factors can trigger DTC P0123, including:

• Faulty throttle position sensor
• Wiring issues such as short circuits or open circuits in the TPS circuit
• Corroded or loose electrical connectors
• Faulty Engine Control Module (ECM)
• Mechanical issues with the throttle body

DTC P0123 seriousness

DTC P0123 is considered a serious issue as it can affect the vehicle’s drivability and safety. The high input signal from the TPS can lead to unpredictable throttle response, which may result in difficulty controlling the vehicle. Additionally, prolonged driving with this code can cause further damage to the engine or transmission components. It is advisable to address this code promptly to ensure safe operation.

How to diagnose DTC P0123

To diagnose DTC P0123, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the P0123 code.
2. Inspect the throttle position sensor and its wiring for visible damage or corrosion.
3. Check the electrical connectors for secure connections and signs of wear.
4. Test the TPS using a multimeter to ensure it operates within the specified voltage range.
5. Examine the throttle body for any mechanical obstructions or sticking.
6. Clear the code and perform a road test to see if the code reappears.

How to fix DTC P0123 step-by-step instructions

To fix DTC P0123, follow these steps:

1. Disconnect the battery to ensure safety while working on electrical components.
2. Inspect and repair any damaged wiring or connectors related to the TPS.
3. If the TPS is faulty, replace it with a new sensor.
4. Clean the throttle body to remove any carbon buildup that may affect operation.
5. Reconnect the battery and clear the DTC using an OBD-II scanner.
6. Perform a road test to verify that the issue is resolved and the code does not return.

How to erase DTC P0123

To erase DTC P0123, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Navigate to the “Erase Codes” or “Clear DTCs” option on the scanner.
4. Confirm the action to clear the trouble codes.
5. Disconnect the scanner and start the engine to ensure the code does not reappear.

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