P2122 Code: Throttle/Pedal Position Sensor/Switch ‘D’ Circuit Low Input – How to Fix
Video Tutorial
Watch the full step-by-step diagnosis here:
What is the P2122 Code?
The P2122 diagnostic trouble code indicates that the throttle/pedal position sensor circuit “D” has a voltage reading lower than the expected range. This can cause hesitation, limp mode, or total throttle failure.
Common Symptoms
- Check Engine Light illuminated
- Poor acceleration or hesitation
- Limp mode activation
- Rough idling or stalling
Possible Causes
- Faulty throttle position sensor (TPS) or accelerator pedal sensor
- Damaged or corroded wiring/connectors
- Faulty ECU (less common)
- Moisture intrusion in sensor housing
DIY Fix – Step by Step
- Inspect throttle body and pedal sensor connections for loose or corroded terminals.
- Check voltage and ground signals using a multimeter.
- Replace faulty throttle or pedal position sensor if readings are incorrect.
- Use a professional scanner like iCarsoft CR Max BT to clear the code and verify live data.
- Test drive the vehicle to confirm smooth throttle response.
User Example
A Ford Focus owner reported hesitation and limp mode with code P2122. After checking wiring and confirming a failing accelerator pedal sensor, they replaced it with an OEM part. Using iCarsoft CR Max BT, they cleared the fault and confirmed correct voltage signals. The issue was resolved in under 2 hours without dealer costs.
FAQ – P2122 Throttle/Pedal Position Sensor
1. How serious is the P2122 code?
Moderately severe. It can limit drivability and trigger limp mode, making driving unsafe if ignored.
2. Can I still drive with P2122?
You may be able to, but the car could enter limp mode at any time. It’s best to repair before driving long distances.
3. What is the cost to fix P2122?
Throttle/pedal sensors typically cost $80–$200. Dealer labor adds $150+, while DIY with an OEM part is much cheaper.
4. How do I clear the P2122 code?
After repairs, use a diagnostic scanner like the iCarsoft CR Max BT to clear the code and reset ECU parameters.
5. Can wiring alone cause this issue?
Yes, damaged wiring or corroded connectors are common causes. Always inspect before replacing sensors.
6. How can I prevent P2122?
Perform routine maintenance, keep connectors dry, and avoid using cheap aftermarket sensors.
7. Is this issue common across brands?
Yes. Ford, GM, Toyota, VW, and many other manufacturers see this issue with throttle or pedal sensors.
8. Can cleaning the throttle body fix P2122?
Sometimes. If the sensor itself is functional but clogged with carbon, cleaning may help restore correct readings.
Related Resource
You may also find our in-depth guide on P2122 Code: Throttle/Pedal Position Sensor Low Input helpful for deeper insights and repair tips.
Conclusion
The P2122 code signals a low input from the throttle/pedal position sensor, often linked to wiring faults or sensor failure. With a reliable scan tool like the iCarsoft CR Max BT, you can diagnose, repair, and clear this issue quickly—restoring safe drivability without high repair costs.
