B1478

CONDITIONS FOR RUNNING THE DTC
- The system voltage must be between 9.0 and 16.0 volts.
- The doors must remain closed.
- The ignition switch must be cycled ON to OFF.
- The radio or power windows must be operated to verify operation.

CONDITIONS FOR SETTING THE DTC
- When the BCM detects battery voltage (short to battery) on the RAP relay control circuit with the ignition switch in the RUN position.
- The above conditions must be met for 0.5 seconds.

ACTION TAKEN WHEN THE DTC SETS
The radio, the power windows, the sunroof (if equipped), and OnStar (if equipped) will not operate after the ignition switch is turned OFF and all the doors are closed.

CONDITIONS FOR CLEARING THE DTC
- A history DTC will clear after 100 consecutive ignition cycles without a fault present.
- History and current DTC(s) may be cleared by using a scan tool.

DIAGNOSTIC AIDS
Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent and Poor Connections in Diagrams.

TEST DESCRIPTION

Steps 1-7:

Steps 8-13:

The number(s) below refer to the step number(s) on the diagnostic table.
2. Listen for an audible click when the retained accessory power (RAP) relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. Tests for voltage at the coil side of the RAP relay. The RAP fuse supplies power to the coil side of the RAP relay.
4. Verifies that the Body Control Module (BCM) is providing ground to the RAP relay.
5. Tests if ground is constantly being applied to the RAP Relay.
12. After replacement of the BCM you must calibrate the new module for proper operation.