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P0123

P0123 - Accelerator sensor 1 error (voltage high)

Bosch · ECU Troubleshooting

What does P0123 mean?

The voltage signal from the first accelerator position sensor is too high. This indicates a potential issue with the sensor or its wiring.

Common Causes

  • Faulty accelerator position sensor 1
  • Wiring short to voltage
  • Problem with the ECU's input circuit

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Inspect the accelerator position sensor 1 and its wiring.

  2. 2

    Check for any shorts in the wiring harness.

  3. 3

    Verify the sensor signal voltage against specifications.

Browse all codes in this manual (60)
Verified technical data. Last updated: April 2026

Related Faults

ECU internal faultECU internal fault - Electronic Control Unit internal errorP0008P0008 - No signal on both crankshaft and camshaft speed sensorP0122P0122 - Accelerator sensor 1 error (voltage low)
Source: Bosch ECU Troubleshooting
Open Manual (Page 3)Search more codes in this manual