DTC P0121

Issue Description

The P0121 DTC indicates that the voltage output from the Throttle Position Sensor (TPS) does not match the expected range as compared to the Accelerator Pedal Position (APP) sensor. This miscommunication can confuse the ECM, affecting throttle response and engine performance.

Dodge P0121 Error Code

Causes

  • Faulty Throttle Position Sensor (TPS).
  • Damaged or loose throttle body wiring/connectors.
  • Malfunctioning Accelerator Pedal Position Sensor.
  • Throttle body contamination or obstruction.
  • ECM issues (less common).

Symptoms

  • Check Engine Light (CEL) is On.
  • Hesitation or delayed throttle response.
  • Engine surging or stalling.
  • Reduced engine power (limp mode).
  • Irregular idle speed.

Solutions

    Inspect and clean the throttle body.
  • Test and replace faulty TPS.
  • Check wiring and connectors for damage or looseness.
  • Replace malfunctioning APP sensor if needed.
  • Reset ECM and test drive vehicle.

Dodge Error Codes

  • DTC P0121

    DTC P0121

    Throttle/Pedal Position Sensor A Range/Performance Problem

  • DTC P0128

    DTC P0128

    Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

  • DTC P0171 & P0174

    DTC P0171 & P0174

    Indicate issues related to the air-fuel mixture.

  • DTC P0301-P0308

    DTC P0301-P0308

    Individual cylinder misfires that caused by issues like a bad spark plug or coil, can also point to mechanical or fuel-related problems.