P0121 Subaru Crosstrek
Throttle/Pedal Position Sensor A Range/Performance · Powertrain Code · High · Repair: Moderate
What is P0121?
The TPS is reading outside expected parameters for the current conditions.
When the Subaru Crosstrek triggers code P0121 (throttle/pedal position sensor a range/performance), it typically points to an issue in the powertrain system. This is a high severity code, so address it promptly to avoid further damage or safety concerns. Below you'll find the most common causes, symptoms, and repair options specific to the Subaru Crosstrek.
This repair is rated moderate, meaning some experience and specialty tools required.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Subaru Crosstrek.
Common Causes on Subaru Crosstrek
- Worn throttle position sensor in the electronic throttle body
- Contaminated throttle body bore
- Throttle body wiring issue
- Failing electronic throttle body motor
Symptoms
- Check Engine Light on
- Erratic idle
- Hesitation on throttle tip-in
- Cruise control may not engage
- Limp mode activation
Notes for Subaru Crosstrek
After cleaning or replacing the throttle body, disconnect the battery for 30 seconds to reset the idle adaptation.