P2120 OBD-II: Throttle/Pedal Position Sensor/Switch "D" Circuit

What Does P2120 Code Mean?

OBD-II Code P2120 is defined as a Throttle/Pedal Position Sensor/Switch "D" Circuit

The electronic throttle control system (ETCS) controls the throttle valve opening. When the driver presses the accelerator pedal, the Accelerator Pedal Position Sensor (APP) sends a signal to the engine's control module (PCM) telling the PCM how much power the driver is requesting from the engine. The PCM then commands the throttle plate to open accordingly. If the PCM detects the APP Sensor is not changing appropriately when the accelerator pedal is depressed or released, the PCM will set code P2120. The PCM may also put the engine into "limp home mode", limiting the available power from the engine to prevent unwanted acceleration.

P2120 Symptoms

• Decreased engine performance
• Engine may enter limp home mode (reduced performance)

Common Problems That Trigger the P2120 Code

• Accelerator Pedal Position (APP) assembly failure
• Powertrain Control Module (PCM) failure
• Throttle control motor failure
• Wiring issue