B1478

CIRCUIT DESCRIPTION
The BCM interfaces with the vehicle's power distribution system through the RAP#1 relay. The RAP#1 relay allows the BCM to control the application of power to the teed accessory circuits.

When the ignition switch turns from ON/RUN to LOCK or OFF, with all of the vehicle doors closed, the BCM leaves the RAP#1 relay energized for 20 minutes, or until any vehicle door opens and the BCM detects a ground signal in one of the door ajar circuits.

CONDITIONS FOR RUNNING THE DTC
The BCM must be commanding the RAP#1 relay to energize.

CONDITIONS FOR SETTING THE DTC
- The BCM detects a short to battery in the RAP#1 relay control circuit when the BCM is trying to energize the RAP relay.
- The condition above must be present for more than 300 milliseconds.

ACTION TAKEN WHEN THE DTC SETS
- The RAP#1 relay powered functions will not operate.
- The BCM stores DTC B1478 in memory.

CONDITIONS FOR CLEARING THE DTC
- A current DTC B1478 will clear if the short to battery in the RAP#1 relay control circuit is no longer detected by the BCM when the RAP#1 relay is commanded to energize.
- A history DTC B1478 will clear after the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

TEST DESCRIPTION

DTC B1478 - Steps 1-5:

DTC B1478 - Steps 6-9:

The numbers below refer to the step numbers on the diagnostic table.
2. Listen for an audible click when the RAP#1 relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. This step verifies that the Body Control Module (BCM) is providing ground to the RAP#1 relay.