OBD-II diagnostic trouble code
P0122Caution
Throttle/Pedal Position Sensor A Circuit Low Input
The throttle (or accelerator pedal) position sensor's signal is reading lower than it should — the computer sees this as an implausible/low voltage condition. On drive-by-wire cars especially, this can affect how the engine responds to your right foot.
Symptoms
- Reduced engine power or the car entering a "limp mode" with capped RPM/speed
- Hesitation or a delayed response when pressing the accelerator
- Rough or unstable idle
- In some cases, the engine may not rev past idle at all until the fault clears
Likely causes
- Corroded, damaged, or loose connector at the throttle body or pedal sensor
- A failed throttle position sensor or pedal position sensor
- A short circuit to ground somewhere in the sensor's wiring harness
How to diagnose it
- Check the connector at the throttle body (or under the accelerator pedal) for corrosion or a loose fit first
- Test the sensor's voltage output across its full range of motion with a multimeter or scan tool
- Check the wiring harness for a short to ground if the sensor itself tests within spec
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Code names are compiled from open/standardized SAE and ISO references. Explanations, symptoms, causes and fixes are original. Covers generic (P0/C0/B0/U0) codes only — manufacturer-specific codes are planned for a future update.
Frequently asked questions
Can I drive with P0122?
You can usually keep driving with P0122, but don't put it off — the underlying cause can get worse or lead to further damage the longer it goes unaddressed. Get it diagnosed as soon as you reasonably can.
How much does it cost to fix P0122?
Typical repair costs for {code} range from roughly 60 to 250 EUR, depending on the specific cause and your car — see the fixes listed above for a breakdown.
What causes P0122?
Corroded, damaged, or loose connector at the throttle body or pedal sensor A failed throttle position sensor or pedal position sensor A short circuit to ground somewhere in the sensor's wiring harness
Reviewed by Artyom SemenovAutomotive Editor · Fact-checked by Yauheni Kapliarchuk, Editor-in-Chief