This bulletin applies to 2018 and prior Chevy Bolt EV vehicles (as well as a number of other GM vehicles). The MIL may be on, accompanied by DTC P2138 (accelerator pedal position sensor 1-2 correlation) set as current or history.
This condition is caused by water intrusion into the instrument panel to body harness connector, which carries the accelerator pedal position (APP) sensor signals to the ECM/PCM. This water intrusion results in a voltage difference between APP sensor 1 and APP sensor 2 that exceeds a predetermined value for more than a calibrated period of time, setting P2138. Note that aftermarket equipment can generate this DTC.
Verify that no aftermarket equipment is connected to any of the APP sensor signal or low reference circuits or to any other ECM/PCM 5V reference circuits. Perform a diagnostic system check. If any 5V reference DTCs are set, refer to the DTC list. If any 5V reference DTCs are not set, locate the IP (instrument panel) body harness connector. Inspect for a water leak in that area. If necessary, use a water hose to determine the source of the leak. If a leak is found, repair as needed.
Inspect the IP to body harness connector terminals for corrosion and debris and repair as needed.
