P0123 - Throttle/Pedal Position Sensor/Switch A Circuit High Input

Meaning of P0123 Code

The P0123 code indicates that the Engine Control Module (ECM) has detected a high voltage input from the Throttle/Pedal Position Sensor/Switch A circuit. This means the throttle position sensor (TPS) is sending an abnormally high voltage signal to the ECM, which could cause poor engine performance, stalling, or increased fuel consumption.

Step 1: Gather Necessary Tools

To diagnose and fix the P0123 code, you'll need the following tools:

• Diagnostic scan tool
• Multimeter
• Basic hand tools

Step 2: Perform a Preliminary Inspection

Visually inspect the throttle body and TPS for any obvious damage, wear, or loose connections. Also, check the wiring and connectors for any signs of damage or corrosion.

Step 3: Use a Diagnostic Scan Tool

Connect the diagnostic scan tool to the vehicle's OBD-II port and retrieve any stored trouble codes and freeze frame data. This information can help you determine when the problem occurred and under what conditions.

Step 4: Test the Throttle Position Sensor (TPS)

Using a multimeter, test the TPS for proper voltage and resistance values according to the manufacturer's specifications. If the TPS is not within the specified range, it may need to be replaced.

Step 5: Inspect the Wiring and Connectors

Check the wiring and connectors between the TPS and the ECM for any signs of damage or corrosion. Repair or replace any damaged wiring or connectors as needed.

Step 6: Clear the Code and Test Drive

Once the issue has been resolved, use the diagnostic scan tool to clear the P0123 code. Test drive the vehicle to ensure the problem has been fixed and the code does not return.

Step 7: Additional Considerations

If the problem persists after completing the steps above, you may need to consult with a professional mechanic or refer to the vehicle's service manual for more specific diagnostic procedures.