Circuit/System Verification
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0641 or P0651 are not set.
- If a DTC is set, refer to DTC P0641 or P0651 (ECM) for further diagnosis.
- Observe the scan tool APP Sensor 1 and 2 voltage parameters. Verify both of the APP sensor voltages are between 0.32-4.75 V.
- Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release pedal. Repeat the procedure several times. DTCs P2120, P2122, P2123, P2125, P2127, P2128, or P2138 should not set.
- Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times. DTCs P2120, P2122, P2123, P2125, P2127, P2128, or P2138 should not set.
- Observe the scan tool APP sensor 1 and 2 parameter. The scan tool should display Agree.
- Clear the DTCs with the scan tool. Operate the vehicle within the Conditions for Running the DTC or within the conditions that you observed from the Freeze Frame/Failure Records.
- Ignition ON, observe the DTC information with a scan tool. Verify that DTC P2120 or P2125 are not the only APP sensor DTCs set.
- If DTC P2120 or P2125 are the only DTCs set, replace the ECM.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.