I have recently replaced the gas pedal sensor, throttle body, and associated sensors. Despite these replacements, my Chevy Impala is still displaying error codes P2112 and P2109. The ECM appears to be non-responsive, and no engine functions are working properly. I'm looking for troubleshooting advice on how to resolve this issue or identify the root cause of these specific fault codes.
The original diagnosis from a 3.5L V6 technician indicated that the ECM was receiving faulty voltage signals from the gas pedal sensor, which has since been replaced. The throttle body and associated sensors were also replaced. After replacing the ECM, the same P2112 and P2108 codes persist. Could there be an underlying wiring or grounding issue?
With the key off and engine off (KOEO), what is the voltage reading at these terminals? Please test: APP switch terminal F (WH/BK wire), CKP sensor terminal A (PU/WH wire), throttle body connector terminal E (GY wire). These readings can help determine if there are signal or power issues affecting the ECM.
Are only P2112 and P2108 present, or have any other diagnostic trouble codes been triggered? Confirming the full list of codes will assist in diagnosing whether this is an isolated issue or part of a broader system failure.
Could you clarify which engine variant you have? (e.g., 3.5L V6) This helps narrow down potential causes related to sensor and ECM behavior.