Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
RAP Relay Coil Control | B1475, 1 | 1 | 2 | -- |
Battery Positive Voltage (Relay Output) | 3 | 4 | 2 | -- |
Accessory Voltage (Relay Output) | 3 | 4 | 2 | -- |
Accessory Voltage (Relay Output) | 3 | 4 | 2 | -- |
Accessory Voltage (Relay Output) | 3 | 4 | 2 | -- |
Accessory Voltage (Relay Output) | 3 | 4 | 2 | -- |
Ground (RAP Relay) | -- | 1 | -- | -- |
| ||||
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 I/P fuse block. The relay switched output feeds the SUNROOF, KEY CAPTURE, DSRVM, PWR WIN DRVR, and the PRW WIN PASS fuses within the 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 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 subsystems using RAP.
Diagnostic Aids
| • | The radio and window RAP function are separate RAP functions controlled by serial data and the specific module. These functions are not effected by the BCM RAP relay circuits. |
| • | A short to ground or open/high resistance in the RAP relay switched voltage circuits will cause only part of the RAP functions to be inoperative. Diagnose these symptoms within the respective system sections. |
| • | 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
Connector End View Reference
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.
| ⇒ | If the courtesy lamp operation is incorrect from the drivers door, refer to Courtesy Lamps Malfunction. |
Relay RAP
- Ignition ON, observe the scan tool parameters listed below while opening and closing each vehicle door. The reading should change appropriately between High/Low.
- 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.
Module/Parameter
| • | Driver Door Switch |
| • | Liftgate Ajar Switch |
| • | Pass Door Switches |
| ⇒ | If any parameter does not change as specified, refer to Door Ajar Indicator Malfunction. |
| ⇒ | If the parameter does not respond as specified, replace the BCM. |
Circuit/System Testing
- Ignition OFF, disconnect the RAP Relay.
- Test for less than 2 ohms of resistance between ground circuit terminal 108 and ground.
- Connect a test lamp between the RAP relay control circuit terminal and ground.
- With the driver and passenger doors open, cycle the ignition key ON and OFF. The test lamp should turn ON and OFF when cycling the ignition switch.
- Connect a test lamp between the relay output voltage circuit terminal and ground. The test lamp should not illuminate.
- If all circuits test normal, test or replace the RAP relay.
| ⇒ | If greater than specified, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp remains ON all the time, test the relay coil control circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp remains OFF all the time, test the relay coil control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp illuminates, test the following relay output circuits for a short to voltage: |
| • | Battery positive voltage |
| • | Accessory voltage |
Component Testing
Relay Test
- Ignition OFF, disconnect the RAP relay.
- Test for 70-110 ohms of resistance between terminals 85 and 86.
- Test for infinite resistance between the following terminals:
- Install a 20 amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 5.0 ohms of resistance between terminals 30 and 87.
| ⇒ | If the resistance is not within the specified range, replace the relay. |
| • | 30 and 86 |
| • | 30 and 87 |
| • | 30 and 85 |
| • | 85 and 87 |
| ⇒ | If not the specified value, replace the relay. |
| ⇒ | If greater than specified, replace the relay. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
| • | Control Module References for module replacement, setup, and programming |
