OBD-II Error Code P2122: How to Fix Pedal Position Sensor D Low Signal

Medium 30-60 minutes Medium Severity Verified June 2026
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Error Code
P2122
Brand
OBD-II Generic
Product Type
automotive
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
30-60 minutes
Error code P2122 indicates that the Engine Control Module (ECM) has detected a low voltage signal from the 'D' pedal position sensor. This typically points to a faulty accelerator pedal position sensor, a wiring issue, or a loose connector. You can often fix this yourself by checking the sensor and its connections.
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Tools You'll Need

How to Fix Error Code P2122

  1. Check Diagnostic Trouble Codes (DTCs)

    Ensure the vehicle is parked on a level surface and the ignition is off before connecting the scanner.

  2. Inspect the Accelerator Pedal Connector

  3. Test the Sensor Voltage

    Be careful not to short circuit any pins. Use a wiring diagram specific to your vehicle.

  4. Inspect Wiring for Damage

    Disconnect the battery negative terminal before repairing wiring to avoid shorts.

  5. Replace the Accelerator Pedal Position Sensor

    Some vehicles require recalibration after replacement. Consult your service manual.

Parts You May Need

Accelerator Pedal Position Sensor (assembly)
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OBD2 Scanner
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Accelerator Pedal Position Sensor (assembly)
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OBD2 Scanner
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Accelerator Pedal Position Sensor (assembly)
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OBD2 Scanner
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Accelerator Pedal Position Sensor (assembly)
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OBD2 Scanner
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When to Call a Professional

If you've checked connectors, wiring, and replaced the sensor but the code persists, the issue may be with the ECM itself. A professional mechanic can perform advanced diagnostics to pinpoint the fault.

Frequently Asked Questions

Can I drive with a P2122 code?
It is not recommended. The vehicle may enter limp mode with reduced power or run erratically, posing a safety risk. Have it diagnosed promptly.
What causes P2122?
Common causes include a faulty accelerator pedal position sensor, damaged wiring or connectors, poor electrical connections, or a malfunctioning ECM.
How much does it cost to fix P2122?
If you DIY, the sensor costs $50-$200. A mechanic may charge $100-$200 for labor, so total could be $150-$400 depending on the vehicle.
Is P2122 the same for all cars?
The code definition is standard across OBD-II vehicles, but sensor location and wiring may vary. Always consult your vehicle's service manual.
Do I need to recalibrate after replacing the pedal sensor?
Some vehicles require a recalibration procedure using a scan tool. Check your vehicle's service information. If not done, the code may return.

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