Power and Ground Distribution: Testing and Inspection
Retained Accessory Power (RAP) Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.
Circuit/System Description
The body control module (BCM) monitors the ignition mode signal from the ignition mode switch, battery condition and the doors status to determine whether RAP should be initiated. The BCM controls the auxiliary accessory power (AAP) relay. The AAP relay switched output feeds the 20A CIGAR LIGHTER Fuse, 20A AUXILIARY POWER Fuse, 15A FLDG TOP/TRUNK LATCH Fuse, and the 10A COLUMN LK MODULE (EUROPE) Fuse located in the I/P fuse block.
Reference Information
Schematic Reference
Power Moding Schematics (Power Moding Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
* Retained Accessory Power (RAP) Description and Operation (Retained Accessory Power (RAP) Description and Operation)
* Power Mode Description and Operation (Power Mode Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information.
Circuit/System Testing
1. Close all doors, with a scan tool verify the door ajar switch parameters are all closed.
• If not the specified parameter, refer to Symptoms - Vehicle Access (Symptoms - Vehicle Access) .
2. Ignition OFF, Disconnect the APP relay.
3. Ignition OFF, test for less than 5.0 ohm of resistance between the ground circuit terminal A1 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
4. Ignition ON, verify a test lamp does not illuminate between the control circuit terminal A2 and ground.
• If the test lamp illuminates, test the control circuit for a short to voltage.
5. Verify a test lamp illuminates between the B+ circuit terminal C1 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the control circuit terminal A2 for a short to ground.
6. Connect a 60A fused jumper wire between the B+ circuit terminal C1 and the control circuit terminal A2.
7. Remove the FLDG TOP/TRUNK LATCH Fuse.
8. Verify a test lamp illuminates between the FLDG TOP/TARUNK LATCH Fuse and ground.
• If the test lamp does not illuminate, test the control circuit for an open/high resistance.
9. Connect a test lamp between the control circuit terminal C2 and the ground circuit terminal A1.
10. Close all doors, cycle the ignition key to the RUN position, test lamp should illuminate. Cycle ignition to the OFF position, wait approximately 10 seconds, test lamp should remain illuminated. Open the driver door, test lamp should turn OFF.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
11. If all circuits test normal, test or replace the APP relay.
Component Testing
Relay Test
1. Ignition OFF, disconnect the AAP relay.
2. Ignition OFF, test for 70-110 ohms of resistance between terminals 85 and 86.
3. If the resistance is not within the specified range, replace the relay.
4. Test for infinite resistance between the following terminals:
* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87
• If not the specified value, replace the relay.
5. Test for less then 2 ohms of resistance between terminals 30 and 87A
• If greater then the specified range, replace the relay.
6. Install a 60-amp fused jumper wire between relay terminal 85 and 12 volts.
7. Install a jumper wire between relay terminal 86 and ground.
8. Ignition OFF, Test for less than 2 ohms of resistance between terminals 30 and 87.
• If greater then 2 ohms, replace the auxiliary power relay.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning)for BCM replacement, setup, and programming