Diagnostic Instructions
Diagnostic Fault Information
Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
| Signal Performance
|
Accessory Voltage
| B1475
| 1
| 2
| --
|
- Partial or all relay controlled RAP functions inoperative depending on location of open.
- Relay RAP remains on past the timer limit after key out and will not turn off when a vehicle door is opened.
|
Circuit/System Description
The retained accessory power (RAP) system allows specific vehicle functions to operate after the ignition is turned OFF for a predetermined time. The RAP relay is internal to the BCM. Relay RAP is controlled by the BCM using inputs from the door ajar switches
to determine control of the relay when the ignition is turned OFF. Radio RAP is controlled by a serial data message from the BCM using inputs from the driver door open switch. Refer to
Retained Accessory Power (RAP) Description and Operation for more detail on RAP operation.
Diagnostic Aids
• | Window (with RPO AN3) and radio RAP functions are separate RAP functions controlled by serial data messages and the specific module. These functions are not effected by the BCM internal RAP relay circuit. |
• | Window RAP (without AN3) function is controlled by the BCM internal RAP relay. |
Reference Information
Schematic Reference
Power Moding Schematics
Connector End View Reference
Power and Grounding Connector End Views
Electrical Information Reference
Circuit/System Verification
Important: Battery voltage must remain above 9.6 V for RAP to operate properly.
Radio RAP
- With all passenger doors closed, observe the courtesy lamps while opening and closing the driver door. The courtesy lamps should illuminate when the door is opened and turn off approximately 30 seconds after closing the door.
- If courtesy lamp operation is correct, and the radio is the only RAP concern, replace the radio.
Relay RAP
- Ignition ON, observe the following scan tool parameters in the BCM while opening and closing each vehicle door. The reading should change appropriately between Door Closed/Door Ajar.
• | Left Rear Door Ajar Sw. |
• | Passenger Door Ajar Sw. |
• | Right Rear Door Ajar Sw. |
- Command the scan tool Accy/RAP Relay OFF. Attempt to operate any RAP relay controlled component within 5 seconds. The component should not operate.
- Command the scan tool Accy/RAP Relay ON. Attempt to operate any RAP relay controlled component within 5 seconds. The component should operate.
- Ignition ON, all doors closed. Observe the scan tool parameter Accy/RAP Relay Command. Ignition OFF, key removed, the reading should remain ON for approximately 10 minutes then change to OFF.
⇒ | If the parameter does not respond as specified, replace the BCM. |
Circuit/System Testing
- Ignition OFF, disconnect harness connector X2 of the right I/P junction block.
- Connect a test lamp between the accessory voltage circuit terminal B3 (component side) and ground.
- Command the scan tool Accy/RAP Relay ON and OFF. the test lamp should cycle on and off as appropriate.
⇒ | If the test lamp is always ON, test the accessory voltage circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
⇒ | If the test lamp is always OFF, test the accessory voltage circuit for a short
to ground or open/high resistance. If the circuit tests normal, replace the BCM. |
- If equipped with a sunroof, connect a test lamp between the accessory voltage circuit terminal B3 (harness side) and ground. The test lamp should not illuminate.
⇒ | If the test lamp illuminates, test the accessory voltage circuit for a short to voltage. |
- If all circuits test normal, replace the BCM.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for module replacement, setup, and programming