P2124 - OBD II Trouble Code

January 31, 2017

Our automotive experts have put together the following information about the P2124 diagnostic trouble code. We've provided the common symptoms that occur when this code is set along with the frequent repairs that address the issues related to the P2124 code.

OBD II Fault Code

  • OBD II P2124

OBD-II Code Decreased engine performance is defined as a Throttle/Pedal Position Sensor/Switch "D" Circuit Intermittent

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 P2124. The PCM may also put the engine into "limp home mode", limiting the available power from the engine to prevent unwanted acceleration.

Decreased engine performance Symptoms

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

Common Problems That Trigger the P2124 Code

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

About the Author

Brad Kava is an automotive expert at RepairPal, the leading online source of auto repair resources and estimates. With many ASE Master certified mechanics on staff who have decades of experience, RepairPal knows all the fine points of car repair.

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