Diagnostic Instructions
Diagnostic Fault Information
Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
| Signal Performance
|
RAP Relay Coil Control
| B1475, 1
| 1
| 2
| --
|
Accessory Voltage (Relay Output)
| 3
| 4
| 2
| --
|
Ground (RAP Relay)
| --
| 1
| --
| --
|
- All relay controlled RAP functions inoperative.
- Relay RAP remains on past the timer limit after key out and will not turn off when a vehicle door is opened.
- All relay controlled RAP functions inoperative with open fuse.
- Partial or all relay controlled RAP functions inoperative depending on location of open, with fuse OK.
|
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 located in the underhood fuse block. The relay accessory voltage (output) feeds the RAP fuse
and the RUN/ACCY fuse 42 within the underhood fuse block. 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 notified by a serial data message from
the BCM, then controlled by the radio to determine radio RAP timing.
Diagnostic Aids
| • | The radio RAP function is a separate RAP function controlled by serial data and the specific module. These functions are not effected by the BCM RAP relay circuits. |
| • | A short to voltage on the RAP relay control or switched voltage circuits would cause the RAP function to remain on past the designated time. |
| • | A stuck relay switch could cause a RAP always on, or a RAP inoperative condition. |
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.
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 appropriate scan tool parameters listed below while opening and closing each vehicle door. The reading should change between Door Closed/Door Ajar.
Parameter
| • | 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 be ON for approximately 10 minutes then change to OFF.
| ⇒ | If the parameter does not respond as specified, replace the BCM. |
Circuit/System Testing
- Verify the RUN/ACCY fuse in the underhood fuse block is not open.
| ⇒ | If the fuse is open, refer to Accessory Circuit Test. |
- Remove the RUN/ACCY fuse and place the ignition switch in the RUN position. Verify that the ignition switch will not return to the OFF position.
| ⇒ | If the ignition switch returns to the OFF position, refer to Accessory Circuit Test. |
- Connect a 3-amp fused jumper wire to the output terminal of the RUN/ACCY fuse. Verify that the ignition switch will return to the OFF position.
| ⇒ | If the ignition switch will not return to the OFF position, refer to Accessory Circuit Test. |
- Ignition OFF, disconnect the harness connector X5 at the BCM.
- Ignition ON, test for less than 1 volt between the input terminal of the RUN/ACCY fuse and ground.
| ⇒ | If greater than the specified range, test the relay control circuit for a short to voltage. If the circuit tests normal, replace the underhood fuse block. |
- Test for 70 - 130 ohms between the RAP/ACCY relay coil control circuit terminal 11 and ground.
| ⇒ | If less than the specified range, test the control circuit for a short to ground. If the circuit tests normal, replace the underhood fuse block. |
| ⇒ | If greater than the specified range, test the circuits listed for an open/high resistance. If the circuits test normal, replace the underhood fuse block. |
Accessory Circuit Test
- Ignition OFF, remove the RUN/ACCY fuse in the underhood fuse block.
- Ignition ON, verify that a test lamp does not illuminate between the output terminal of the fuse and ground.
| ⇒ | If the test lamp illuminates, test the accessory circuit for a short to voltage. |
- Verify that a test lamp does not illuminate between the output terminal of the fuse and B+.
| ⇒ | If the test lamp illuminates, disconnect the harness connector listed one at a time and verify the test lamp remains illuminated after each disconnect. If the test lamp turns off after a disconnect, replace the last component disconnected. If the
test lamp remains illuminated after all components are disconnected, test the accessory circuit for a short to ground. |
| • | Automatic transmission shift lever |
| • | Midgate window switch - RPO SUT |
| • | Midgate control module - RPO SUT |
| • | Sunroof module - RPO CF5 |
- Test the accessory circuit for an open/high resistance.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the repair.
