B1475

DTC B1475

CIRCUIT DESCRIPTION
The body control module (BCM) controls various accessories through the retained accessory power (RAP) relay circuit. When the ignition switch is in either the ACC or the ON position, the BCM provides battery negative voltage to the RAP relay control circuit. When the RAP relay is energized, it supplies a B+ to the accessories not controlled by a serial data power mode message.

When the ignition switch turns from ON or ACC to OFF, with all of the vehicle doors closed, the BCM keeps the relay energized for 10 minutes, or until any vehicle door opens.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B1475 Retained Accessory Power Circuit

CONDITIONS FOR RUNNING THE DTC
The system voltage must be between 9-16 volts.

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

ACTION TAKEN WHEN THE DTC SETS
- The BCM stores DTC B1475 in memory.
- The devices powered by the RAP supply voltage circuit will not operate.

CONDITIONS FOR CLEARING THE DTC
- A current DTC clears when the malfunction is no longer present.
- A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

TEST DESCRIPTION

Step 1 - Step 11:

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 RAP fuse supplies power to the coil side of the RAP relay.
4. This step verifies that the BCM is providing ground to the RAP relay.
5. This step tests the control circuit side of the RAP relay for faults that cause both B1475 RAP DTC.
10. After replacement of the BCM you must calibrate the new module for proper operation.