GM Service Manual Online
For 1990-2009 cars only

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.

Circuit/System Description

The retained accessory power (RAP) relay is located in the I/P fuse block. The relay control is from the body control module (BCM). The relay switched output feeds the RSE fuse 10A, Power Sunroof fuse 20A, and the PWR/WINDW circuit breaker within the I/P fuse block.

Diagnostic Aids

    • A short to ground in the accessory voltage circuit should cause an open fuse or circuit breaker causing only part of the RAP functions to be inoperative.
    • An open in the in the either accessory voltage circuit will cause inoperative conditions effecting only part of the RAP functions to be inoperative.
    • A short to voltage on the relay control or relay output circuits would cause the RAP function to remain on past the designated time.
    • An stuck relay switch could cause a RAP always on, or a RAP inoperative condition.

Reference Information

Schematic Reference

    •  Power Distribution Schematics
    •  Power Moding Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Retained Accessory Power (RAP) Description and Operation

Electrical Information Reference

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

Circuit/System Testing

Important: If any door open switch input to the BCM is reporting a door open when it is not the RAP function will not operate after the key is turned off or removed and the courtesy lamps will remain on longer than 30 seconds after exiting the vehicle and closing all doors. Before continuing diagnosis, ensure that the courtesy lamps turn off properly after closing all doors. If courtesy lamps remain on, refer to Symptoms - Lighting.

  1. Ignition OFF, disconnect the harness connector at the BEC.
  2. Test for less than 1 ohm of resistance between the relay coil ground circuit and ground.
  3. If greater than 1 ohm, repair the ground circuit for an open/high resistance.
  4. Connect a test lamp between the RAP relay control circuit and ground. Close all vehicle doors.
  5. Observe the test lamp, cycle the ignition key to the RUN position and back to the OFF position, wait 10 seconds, open the driver door. The test lamp should turn ON when key is in RUN, and remain on until the driver door is opened.
  6. If the test lamp is always ON, test the relay coil control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
    If the test lamp is always OFF, test the relay coil control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM.
  7. If all circuits test normal, test or replace the BEC.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for module replacement, setup, and programming