P2138 Fault on 2009 Chevrolet Impala: Intermittent Traction Control Failure and Power Loss
My 2009 Chevrolet Impala recently experienced a sudden loss of power and 'traction control not operating' for approximately one mile. After shutting off the engine and restarting it, the vehicle stored Diagnostic Trouble Code (DTC) P2138. This code cleared after about 50 miles of driving, and all systems have returned to normal since then. The issue appears to be intermittent, with no consistent pattern under normal conditions. I am concerned this could occur on the freeway, which would be dangerous. What steps should I take to diagnose and resolve this? Should the dealership perform a full inspection or is there a simpler fix at the owner level?
DTC P2138 indicates a correlation issue between Accelerator Pedal Position (APP) Sensor 1 and APP Sensor 2. To troubleshoot, inspect the wiring harnesses and connectors for both sensors. Perform a 'wiggle test' while driving to simulate the fault condition. Additionally, ensure the floor mat is not obstructing the accelerator pedal, as this can cause sensor misreading.