The P2165 code indicates that the Powertrain Control Module (PCM) has detected an abnormal voltage signal from the Throttle Pedal Position Sensor C when the accelerator pedal is at its maximum stop (idle) position. This suggests the sensor or its circuit is not reading the expected full-range value, possibly due to a faulty sensor, wiring issue, or mechanical problem. The vehicle may enter a fail-safe mode to prevent unsafe operation.
The sensor inside the pedal assembly may be worn, contaminated, or failed, sending incorrect voltage signals.
Damaged, corroded, or loose wiring/connectors to the sensor can cause open or short circuits.
A sticky, worn, or misaligned pedal mechanism can prevent the sensor from reaching its full range.
Outdated or corrupted PCM software may misinterpret sensor data; reprogramming may resolve.
Rarely, the PCM itself may be defective; this is a diagnosis of exclusion after all other causes are ruled out.
The vehicle may run in reduced-power mode; short distances are possible, but have it diagnosed promptly.
Usually not; most issues are with the sensor or wiring; PCM replacement is rarely needed and should be a last resort after confirming other causes.
Yes, debris or wear in the pedal mechanism can interfere with the sensor's movement and cause incorrect readings.
Because the symptom is an out-of-range sensor signal, technicians may incorrectly assume the PCM is faulty; however, sensor or wiring problems are far more common.