P2136 is set when the PCM detects that the voltage signals from two throttle‑pedal position sensor circuits (commonly labeled A and C) do not agree within the expected range. The mismatch can stem from a faulty sensor, damaged wiring, improper reference voltage, or a ground problem, and it forces the PCM into a reduced‑power mode to protect the engine.
The sensor itself can develop internal resistance changes or mechanical wear, producing incorrect voltage signals that no longer correlate with the other circuit.
Open, shorted, or corroded wires and poor connector contacts can distort the voltage readings of the sensor circuit.
If the 5 V supply that powers the sensor is interrupted, grounded, or otherwise out of specification, both sensor signals will be erroneous.
Insufficient ground at the sensor or PCM can cause voltage offsets that make the two signals appear mismatched.
The pedal assembly houses both sensor circuits; physical damage or wear in the assembly can affect both signals simultaneously.
An internal fault in the PCM’s input circuitry can produce false correlation codes, but this is the least likely cause and should only be considered after all other sources are eliminated.
You can continue driving short distances, but the vehicle may be in a reduced‑power mode, experience poor throttle response, or stall. Prompt diagnosis and repair are recommended.
Often yes, but the fault can also be in the wiring, connectors, 5 V supply, or ground. Proper verification of those items should be done before assuming the sensor is the sole cause.
No. PCM failures are an uncommon cause of P2136. In the vast majority of cases the issue lies with the sensor, its wiring, or its power/ground supplies. Only after all other possibilities are ruled out should PCM replacement be considered.
Yes. If the sensor’s reference voltage is out of spec or its ground is inadequate, the voltage signals will be incorrect, triggering a correlation code even when the sensor is functioning properly.