GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Power Distribution Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Do only the devices powered by the accessory relay exhibit this symptom?

Go to Step 4

Go to Step 3

3

  1. Install a scan tool. Select body control module (BCM) data in data display.
  2. Close all the doors.
  3. Turn ON the ignition, with the engine OFF.
  4. Wait 5 seconds, then turn the ignition OFF.
  5. Wait for the retained accessory power (RAP) time-out.

Does the scan tool display the Accessory power mode, then time-out, and display Off-Awake or OFF power mode?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 10

4

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the accessory relay.

Do the devices controlled by the Accessory relay operate?

Go to Step 5

Go to Step 6

5

Repair the short to battery in the accessory relay switched output circuit. Refer to Wiring Repairs .

Did you complete the repair?

Go to Step 12

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6

  1. Open the driver door.
  2. Connect a test lamp across the relay coil circuits of the Accessory relay socket.

Does the test lamp illuminate?

Go to Step 7

Go to Step 8

7

Test the accessory relay control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 10

8

Inspect for poor connections at the accessory relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 9

9

Replace the accessory relay.

Did you complete the replacement?

Go to Step 12

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10

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 11

11

Important: Perform the module setup procedure, if required.

Replace the BCM. Refer to Body Control Module Replacement .

Did you complete the procedure?

Go to Step 12

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12

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2