P2122
Accelerator Pedal Position Sensor Circuit Low Input
The car is not getting the correct signal from the accelerator pedal sensor. This can keep the throttle from responding normally and can trigger reduced power mode. The problem is usually in the pedal sensor, wiring, or a related connector.
- SEV
- 4/5
- DRIVE
- CAUTION
- DIY
- $20–$250
- SHOP
- $150–$650
Quick answer
AI-CITATION READYWhat it means
Can you drive with it?
Most common causes
- Faulty accelerator pedal position (APP) sensor or accelerator pedal assembly
- Wiring damage, corrosion, loose connector, or poor terminal contact in the APP circuit
- Throttle body or throttle control motor problem affecting throttle response and related signals
Typical repair cost
DIY usually runs $20–$250. Typical shop repair lands around $150–$650, depending on the root cause.
01 / Definition
P2122 indicates the PCM has detected a low voltage or low input signal in accelerator pedal position circuit A. This usually means the signal from the APP sensor is below the expected range, which prevents the PCM from accurately controlling throttle response. The cause may be a failing accelerator pedal assembly, damaged wiring, poor connector contact, throttle control issues, or a PCM fault.
02 / Drive status
With caution. You may be able to move the vehicle, but acceleration can be limited or unpredictable. Avoid highway driving and get it diagnosed soon, because the engine may enter reduced power mode.
03 / Symptoms
- Check engine light
- Reduced engine power or limp mode
- Poor throttle response
- Engine hesitation or surging
- Limited acceleration
- Cruise control may not work
- Stalling or hard starting in some cases
04 / Causes
| 1 | Faulty accelerator pedal position (APP) sensor or accelerator pedal assembly | high |
|---|---|---|
| 2 | Wiring damage, corrosion, loose connector, or poor terminal contact in the APP circuit | high |
| 3 | Throttle body or throttle control motor problem affecting throttle response and related signals | medium |
| 4 | Contaminated or damaged connector pins at the pedal sensor, throttle body, or PCM | medium |
| 5 | PCM failure or internal reference voltage problem | low |
05 / Diagnostic sequence
- 01Scan for all stored and pending codes, including throttle and pedal sensor codes.
- 02Inspect the accelerator pedal assembly and connector for looseness, corrosion, water intrusion, or broken wiring.
- 03Check live data from the APP sensor and compare pedal position readings for smooth, consistent changes.
- 04Inspect throttle body wiring, connector condition, and throttle plate operation.
- 05Test reference voltage, ground, and signal continuity in the APP circuit with a multimeter.
- 06Clear codes and perform a road test only after repairs are made.
- 07If wiring and sensors test good, verify PCM inputs and consider PCM diagnosis last.
06 / Repairs
| 1 | Repair or replace damaged wiring, terminals, or connectors in the accelerator pedal circuit | $20–$200 |
|---|---|---|
| 2 | Replace the accelerator pedal position sensor or complete pedal assembly if readings are out of range | $80–$300 |
| 3 | Clean or replace the throttle body if throttle movement or throttle control motor operation is faulty | $100–$450 |
| 4 | Update or diagnose the PCM if all other components and wiring test correctly | $150–$650 |
MFG / Manufacturer notes
These supplements add make-specific diagnostic framing. Pages without full matrix backing or lane approval stay guarded and canonicalize back here until they are explicitly approved for indexing.
- Open
Audi P2122
Expansion-candidate noindex child page
07 / Related codes
08 / FAQ
Can a bad battery cause P2122?
A weak battery or charging problem can sometimes contribute to sensor and throttle control issues, but it is usually not the main cause.
Will replacing the throttle body fix P2122?
Not usually. P2122 is more commonly caused by the accelerator pedal sensor or wiring, though throttle system problems can be involved.
Can I clear P2122 and keep driving?
You can clear it, but if the fault is still present the code will return. Driving with this code can leave you with limited power or throttle response.
09 / Source and method
- DATA BASIS
- OBD-II REFERENCE + OBD2.HELP
- METHOD
- STATIC VALIDATION
- SAFETY
- INFORMATIONAL
This page combines OBD-II diagnostic reference data with OBD2.help generated diagnostic guidance for code meaning, likely causes, and repair direction.
Publishing uses deterministic schema and build validation, plus manual spot checks on representative pages before release.
Safety-critical diagnosis and repairs should be confirmed with a qualified mechanic, especially when the vehicle is misfiring, overheating, or losing power.