OBD-II code guide
P0121 Throttle Position Sensor Range or Performance
P0121 means the throttle position signal does not match expected range or behavior.
What it means
The computer sees throttle angle information that may be inaccurate or inconsistent.
Common symptoms
- Reduced power
- Hesitation
- High idle
- Stalling
- Check engine light
Likely causes
- Throttle position sensor fault
- Dirty throttle body
- Wiring issue
- Pedal sensor correlation issue
- Throttle body fault
First checks
- Look for reduced power messages.
- Inspect throttle body connector.
- Check for related throttle or pedal codes.
- Do not force an electronic throttle plate by hand unless service information allows it.