Accelerator Pedal Position Signal Low
The accelerator pedal position signal is lower than expected.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The sensor that reads how far you're pressing the gas pedal isn't sending enough voltage to the engine computer.
What the computer is actually seeing
The engine control unit (ECU) expects a voltage between 0.5V to 4.5V from the accelerator pedal position sensor. A voltage lower than 0.5V indicates a problem.
What a healthy reading looks like
Expected voltage from the accelerator pedal position sensor should range from 0.5V (idle) to 4.5V (full throttle).
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 1Check the accelerator pedal position sensor wiring for any signs of damage or corrosion.
- 2Verify connector integrity; clean and reseat if necessary.
- 3Use a multimeter to test the voltage output from the accelerator pedal position sensor; it should be between 0.5V and 4.5V at various pedal positions.
- 4If signal is low, replace the accelerator pedal position sensor and retest the voltage.
- 5If voltage is normal, check the ECU for faults or replace it if necessary.
Common causes
- Faulty accelerator pedal position sensor
- Wiring issues such as shorts or opens
- Poor connection at the sensor or ECU
- ECU malfunctions
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's generally safe to drive but expect reduced engine performance and responsiveness.
Will this code come back after clearing?
If the underlying issue isn't fixed, yes, it will likely reappear.
Why does this code sometimes pair with SPN 0123?
SPN 0123 indicates a high signal. If SPN 0122 is active, it may indicate sensor malfunction.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
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