Operation CHARM: Car repair manuals for everyone.

Retained Accessory Power Malfunction




Retained Accessory Power Malfunction

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

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 function is directly controlled by the body control module (BCM) through the ignition I/II voltage circuit. RAP is controlled by the BCM using inputs from the door ajar switches to determine control of the ignition I/II voltage circuit 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. The ignition I/II voltage circuit from the BCM feeds the following:

* Windshield wiper/washer switch
* Driver window switch
* Passenger window switch

Reference Information
Schematic Reference

Power Moding Schematics Power Moding Schematics
Connector End View Reference

Component Connector End Views Connector End Views By Name
Description and Operation

Retained Accessory Power Description and Operation Retained Accessory Power
Electrical Information Reference

* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Programming and Relearning for scan tool information

Circuit/System Verification

Ignition OFF, doors closed, observe the operation of the power windows while using the appropriate switches, the power windows should continue to function for 10 minutes after the ignition has been switched to the OFF position.

Circuit/System Testing

1. Ignition OFF, disconnect the Accessory relay.
2. Ignition ON, verify that a test lamp does not illuminate between the relay controlled output circuit terminal and ground.

If the test lamp illuminates, test the control circuit for a short to voltage.

3. Verify that a test lamp illuminates between the Accessory relay coil B+ circuit terminal and ground.

If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

4. Verify that a test lamp illuminates between the Accessory relay switch B+ circuit terminal and ground.

If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.

5. Connect a 50A fused jumper wire between the Accessory relay switch B+ circuit terminal and the relay controlled output circuit terminal. Verify the power windows activate while using the appropriate power window switch.

If the power windows do not activate, test the control circuit for an open/high resistance. If the circuit tests normal, refer to Power Windows Malfunction (Coupe) Power Windows Malfunction (Coupe)Power Windows Malfunction (Sedan) Power Windows Malfunction (Sedan)Power Windows Malfunction (Convertible) Power Windows Malfunction (Convertible).

6. Connect a test lamp between the Accessory relay coil B+ circuit terminal and the Accessory relay control circuit terminal.
7. Command the Accessory relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.
If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

8. If all circuits test normal, test or replace the Accessory relay.

Component Testing

1. Ignition OFF, disconnect the Accessory relay.
2. Test for 60-200 ohms between terminals 85 and 86.

If not within the specified range, replace the relay.

3. Test for infinite resistance between the following terminals:

* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87

If less than the specified value, replace the relay.

4. Install a 3-amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Measure for less than 2 ohms between terminals 30 and 87.

If greater than specified range, replace the relay.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)
* Control Module References Programming and Relearning for BCM replacement, setup, and programming