OBD-II code · Powertrain (generic, extended)
P2121 Throttle/Pedal Position Sensor "C" Range/Performance
The "C" channel of the throttle or pedal sensor produces an electrically valid signal that does not match the other channels or the operating point.
Is it safe to drive with P2121?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor track C worn
- PossibleCorrelation with tracks A/B lost
- Less likelySensor element aged beyond calibration window
Symptoms
- Check engine light on
- Reduced throttle response, possible limp mode
- Hesitation or surging
- Idle too high or too low
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.5 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Accelerator Pedal Sensor
Related codes
- P0121Throttle/Pedal Position Sensor "A" Range/Performance
- P2120Throttle/Pedal Position Sensor "C" Circuit
- P2131Throttle/Pedal Position Sensor "E" Range/Performance
- P211EThrottle Actuator B Control Module Processor
- P211FThrottle Actuator B Control Module Performance
- P2122Throttle/Pedal Position Sensor "D" Circuit Low
- P2123Throttle/Pedal Position Sensor "D" Circuit High
- P2124Throttle/Pedal Position Sensor "C" Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.