B1477

CIRCUIT DESCRIPTION
The BCM interfaces with the vehicle's power distribution system through the RAP relay. The RAP relay allows the BCM to control the application of power to the feed circuits of the Sunroof and power windows. When the ignition switch is in either the ACC or the RUN position, the BCM energizes the RAP relay by grounding the RAP relay control circuit.

The BCM turns off the RAP relay when the ignition switch is in the START position. The RAP feature therefore disables during engine cranking.

When the ignition switch turns from ON to LOCK or OFF, with all of the vehicle doors closed, the BCM leaves the RAP relay energized for 10 minutes, or until any vehicle door opens and the BCM detects a ground signal in one of the door ajar circuits.

CONDITIONS FOR SETTING THE DTC
- The BCM detects no voltage at the RAP relay control circuit when the BCM has not grounded the circuit.
- The conditions above must be present for more than 300 milliseconds.

ACTION TAKEN WHEN THE DTC SETS
- The BCM stores DTC B1477 in memory.
- The circuits powered by the RAP relay remain powered at all times if the relay control circuit is shorted to ground.
- The circuits powered by the RAP relay will never be powered if the relay control circuit is open.

CONDITIONS FOR CLEARING THE DTC
- The correct voltage is present at the RAP relay control circuit as detected by the BCM.
- A history DTC B1477 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

TEST DESCRIPTION

Steps 1-13:

The numbers below refer to the step numbers on the diagnostic table.
2. Listen for an audible click when the RAP relay operates Command both the ON and OFF states. Repeat the commands as necessary.
3. This step tests for voltage at the coil side of the RAP relay. The INADV POWER BUS fuse supplies power to the coil side of the RAP relay.
4. This step verifies that the Body Control Module (BCM) is providing ground to the RAP relay.
5. This step tests if ground is constantly being applied to the RAP relay.