Diagnostic Instructions
Diagnostic Fault Information
Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
| Signal Performance
|
Retained Accessory Power (RAP) Supply Voltage Circuit
| B1477, 1
| 1
| 2
| --
|
- The sunroof will not operate.
- The sunroof will remains on past the timer limit after key out and will not turn off when a vehicle door is opened.
|
Circuit/System Description
The body control module (BCM) controls the sunroof motor operation through the retained accessory power (RAP) supply voltage circuit. When the ignition switch is in either the ACC or the ON position, the BCM provides battery voltage to the RAP supply voltage
circuit. When the ignition switch turns from ON or ACC to OFF, with all of the vehicle doors closed, the BCM still provides battery voltage to the circuit for 10 minutes, or until any vehicle door opens.
| • | Ignition switch is in ACC or ON. |
| • | The vehicle was remote started. |
| • | The vehicle is in RAP mode. |
Diagnostic Aids
| • | A short to voltage on the retained accessory power (RAP) supply voltage circuit would cause DTC B1477 to set, and an inoperative sunroof. |
| • | An open/high resistance in the retained accessory power (RAP) supply voltage circuit will cause an inoperative sunroof. |
| • | A short to voltage on the retained accessory power (RAP) supply voltage circuit would cause the RAP function to remain on past the designated time. |
Reference Information
Schematic Reference
Power Moding Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Retained Accessory Power (RAP) Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for Scan Tool Information
Circuit/System Verification
Important: Battery voltage must remain above 9.6 V for RAP to operate properly.
- With a scan tool, verify that BCM DTC B1477 is not set.
Important: Verify that the interior lamps defeat switch is not activated.
- Observe the courtesy lamps while opening and closing the vehicle doors. The courtesy lamps should illuminate when the doors are opened and turn off approximately 30 seconds after closing.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector of the sunroof module.
- With the ignition key out of the ignition and the driver door open, verify a test lamp does not illuminate between the retained accessory power (RAP) supply voltage circuit terminal 3 of the sunroof module harness connector and ground.
| ⇒ | If the test lamp illuminates, test the ignition circuit for a short to voltage. If the circuit tests normal, test or replace the BCM |
- Ignition ON and the test lamp still connected, verify the test lamp illuminates.
| ⇒ | If the test lamp does not illuminate, test the ignition circuit for a short open/high resistance. If the circuit tests normal, test or replace the BCM |
- If the circuit tests normal, test or replace the sunroof motor.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
