GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Power Moding 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

  1. Close all of the doors.
  2. Turn ON the ignition, with the engine OFF.
  3. Turn OFF the ignition.

Do all the retained accessory power functions operate during the retained accessory power (RAP) mode?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

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

Go to Step 5

Go to Step 4

4

  1. Install a scan tool. Select body control module (BCM) data in data display.
  2. Close all of the doors.
  3. Turn ON the ignition, with the engine OFF.
  4. Wait 5 seconds, then turn the ignition OFF.
  5. Wait for the 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 15

5

  1. Turn OFF the ignition.
  2. Disconnect the accessory relay.
  3. Turn ON the ignition, with the engine OFF.
  4. With a test lamp that is connected to a good ground, probe the battery positive voltage circuit of the accessory relay.

Does the test lamp illuminate?

Go to Step 6

Go to Step 12

6

  1. Connect a test lamp across the relay coil circuit of the accessory relay.
  2. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 9

Go to Step 7

7

Test the accessory relay control circuit for a short to ground or an open.

Turn the ignition ON, with the engine OFF, when testing for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 17

Go to Step 8

8

Test the accessory relay ground circuit for an open.

Did you find and correct the condition?

Go to Step 17

Go to Step 15

9

  1. Turn OFF the ignition.
  2. Reconnect the accessory relay.
  3. Turn ON the ignition, with the engine OFF.
  4. With a test lamp that is connected to a good ground, probe the accessory relay switched output circuit at the accessory relay.

Does the test lamp illuminate?

Go to Step 10

Go to Step 11

10

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

Did you complete the replacement?

Go to Step 17

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11

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 17

Go to Step 14

12

Test the accessory relay switched output circuit for a short to ground.

Did you find and correct the condition?

Go to Step 17

Go to Step 13

13

  1. Repair the battery positive voltage circuit of the accessory relay. Refer to Wiring Repairs .
  2. Reconnect the accessory relay.

Did you complete the repair?

Go to Step 17

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14

Replace the accessory relay.

Did you complete the replacement?

Go to Step 17

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15

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 17

Go to Step 16

16

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 17

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17

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3