P2121 Fault Code

Throttle/Pedal Position Sensor/Switch D Circuit Range/Performance

• What does that mean?
• Symptoms
• Causes
• Solutions

The P2121 fault code indicates a problem with the Throttle/Pedal Position Sensor/Switch D Circuit Range/Performance. This code is triggered when the Engine Control Module (ECM) detects a discrepancy in the voltage signal from the throttle position sensor. The throttle position sensor is critical for ensuring that the engine receives the correct amount of air and fuel, which is essential for proper engine performance and emission control.

What are the symptoms of the P2121 code?

• Decreased engine performance and responsiveness.
• Engine stalling or hesitation during acceleration.
• Check Engine Light illuminated on the dashboard.
• Unusual engine behavior, such as erratic idling or difficulty in maintaining speed.

What causes the P2121 code?

• Wiring issues: Damaged, frayed, or corroded wiring can disrupt the signal.
• Faulty throttle position sensor: The sensor may be malfunctioning and providing inaccurate readings.
• Poor connection: Loose or dirty connectors can cause communication failures.
• ECM issues: In rare cases, the Engine Control Module itself may be at fault if it incorrectly interprets the sensor data.

How to fix P2121?

• Inspect and repair any damaged wiring or connectors associated with the throttle position sensor.
• Test the throttle position sensor for proper functionality and replace it if necessary.
• Clear the fault codes and monitor for reoccurrence.
• If the problem persists, consider evaluating the ECM for potential issues.