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.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

RAP Relay Switch B+

1

1

2

--

RAP Relay Control

B1475 00, 1

1

2

--

RAP Relay Ignition

1

1

2

--

RAP Relay Ground

--

1

--

--

  1. All or partial relay controlled RAP functions might be inoperative depending on the location that the fault occurred.
  2. Relay RAP remains on past the timer limit after key out and will not turn off when a vehicle door is opened.

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 1 relay is located in the I/P fuse block. The relay switched output feeds the WNDW CNTRL Fuse and the WNDW MTR circuit breaker 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.

Diagnostic Aids

The radio RAP mode is a separate function and will still operate properly. The radio RAP function is controlled by serial data and the specific module. These functions are not effected by the BCM RAP relay circuits.

Reference Information

Schematic Reference

Power Distribution Schematics

Power Moding Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Retained Accessory Power Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Radio RAP

  1. 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.
  2. If the courtesy lamp operation is incorrect from the drivers door, refer to Courtesy Lamps Malfunction.
  3. If courtesy lamp operation is correct, and the radio is the only RAP concern, replace the radio.

Relay RAP

  1. Ignition ON, observe the scan tool parameters in the modules listed below while opening and closing each vehicle door. The reading should change appropriately between Door Closed/Door Ajar for the door ajar switches, and between Open/Closed for the door open switches.
  2. Module/Parameter

    • Driver Door Ajar Sw.
    • Driver Door Open Sw.
    • Passenger Door Ajar Sw.
    • Passenger Door Open Sw.
    If any parameter does not change as specified, refer to Door Ajar Indicator Malfunction.
  3. Command the scan tool Accy/RAP Relay OFF. Attempt to operate any RAP relay controlled component within 5 seconds. The component should not operate.
  4. Command the scan tool Accy/RAP Relay ON. Attempt to operate any RAP relay controlled component within 5 seconds. The component should operate.
  5. 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 40 minutes then change to OFF.
  6. If the parameter does not respond as specified, replace the BCM.

Circuit/System Testing

  1. Ignition OFF, disconnect the RAP relay.
  2. Test for less than 5 Ω between the ground circuit terminal 86 and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Connect a test lamp between the relay control circuit terminal 85 and ground.
  5. 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.
  6. 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.
  7. Verify that a test lamp illuminates between the B+ circuit terminal 30 and ground.
  8. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  9. If all circuits test normal, test or replace the RAP relay.

Component Testing

  1. Ignition OFF, disconnect the RAP relay.
  2. Test for 70 - 150 Ω between the control terminal 85 and the ground terminal 86 of the relay.
  3. If not within the specified range, replace the relay.
  4. Test for infinite resistance between the following terminals:
  5. • 30 and 86
    • 30 and 87
    • 30 and 85
    • 85 and 87
    If not the specified value, replace the relay.
  6. Install a 3 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 Ω between terminals 30 and 87.
  7. If greater than specified, replace the relay.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for BCM replacement, setup, and programming.