P2124 indicates an intermittent fault in the 'D' circuit of the throttle/pedal position sensor or switch. The engine control module detects that the signal from this sensor is missing, erratic, or out of range for a period of time, which can affect throttle response.
The sensor itself may develop an internal break or short that only appears under certain pedal positions or temperatures, causing the D‑circuit signal to drop out.
Wires leading to the pedal position sensor can suffer abrasion, pinching, or heat damage, producing an intermittent connection that triggers the code.
Moisture, dirt, or vibration can cause corrosion or a loose fit in the sensor connector, leading to sporadic signal loss.
If the sensor's reference voltage or ground becomes intermittent due to a faulty ground strap or power feed, the PCM may see an invalid signal.
The PCM's internal circuit that reads the sensor signal can fail, but this is uncommon and should be considered only after sensor, wiring, and connector checks are normal.
No. The PCM is rarely the cause of P2124. Most intermittent faults are due to the pedal position sensor, its wiring, or connectors. PCM replacement should only be considered after those components have been verified good.
Clearing the code without fixing the underlying intermittent fault may allow the code to return, and the condition could worsen, potentially leading to stalling or reduced power. It is best to diagnose and repair the issue.
Many pedal position sensors have multiple output circuits (A, B, C, D) for redundancy. The D circuit is one of those signals; an intermittent fault in this specific circuit triggers P2124.
A dirty throttle body does not directly affect the pedal position sensor circuit. However, if the throttle body is stuck or binding, it may cause abnormal pedal sensor readings, but the code itself points to the sensor or its circuit, not the throttle body.