P0121 Nissan Altima
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 Nissan Altima 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 Nissan Altima.
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 Nissan Altima.
Common Causes on Nissan Altima
- Worn throttle position sensor inside the electronic throttle body
- Contaminated throttle body bore and butterfly valve
- Wiring issue between throttle body and ECM
- Failing electronic throttle body motor
Symptoms
- Check Engine Light on
- Erratic idle speed
- Hesitation on acceleration
- Vehicle enters limp mode
- Surging at steady speed
Notes for Nissan Altima
Nissan requires an idle air volume learning (IAVL) procedure after throttle body cleaning; use Consult III or equivalent.