Owners of a 2005-2011 Corvette may comment on an intermittent MIL on with a message or indicator that displays reduced engine power. The technician may find DTC P2138 -- accelerator pedal position (APP) -- sensor 1-2 correlation set as current or in history.
This condition may be caused by water intrusion into the instrument panel to body harness connector, with carries the APP sensor signals to the ECM/PCM. The 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 DTC P2138 and other DTCs. Verify that no aftermarket equipment is connected to any of the APP sensor or low reference circuits or to any other ECM/PCM 5V reference or low reference circuits. Refer to checking aftermarket accessories in the service manual.
Locate the instrument panel to body harness connector, which may be located in and around the left side kick panel area. Some examples of potential water leaks include A-pillar seals, sunroof drain lines and windshield seals. Inspect for a water leak. If necessary use a water hose to determine the source of the leak. Repair the leaks.
Also inspect the instrument panel to body harness connector terminals for corrosion and debris and repair as needed.