GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Body Rear End Schematics

Connector End View Reference: Body Rear End Connector End Views or Body Control System Connector End Views

1

Did you perform the Body Rear End Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Body Rear End

2

Verify that the rear hatch/gate ajar indicator is inoperative.

Does the rear hatch/gate ajar indicator operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Install a scan tool.
  2. Open the lift gate.
  3. Turn on the ignition, with the engine off.
  4. With a scan tool, observe the liftgate ajar switch parameter in the Body Control Module data list.

Does the scan tool display Low?

Go to Step 4

Go to Step 5

4

With a scan tool, command the lamp and gauge check ON in the Instrument Panel Cluster special functions.

Did the liftgate ajar lamp illuminate?

Go to Step 8

Go to Step 9

5

  1. Disconnect the liftgate lock actuator/ajar switch harness connector.
  2. Probe the rear compartment lid ajar switch circuit with a test lamp connected to a good ground.

Did the test lamp illuminate?

Go to Step 6

Go to Step 7

6

Connect a test lamp between the rear compartment lid ajar switch circuit of the liftgate lock actuator/ajar switch harness connector and the ground circuit of the liftgate lock actuator/ajar switch harness connector.

Did the test lamp illuminate?

Go to Step 10

Go to Step 11

7

Test the rear compartment lid ajar switch circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 10

8

Inspect for poor connections at the harness connector of the body control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 12

9

Inspect for poor connections at the harness connector of the instrument panel cluster. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 13

10

Inspect for poor connections at the harness connector of the liftgate lock actuator/ajar switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 14

11

Repair the open in the ground circuit. Refer to Wiring Repairs and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

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12

  1. Perform the set-up procedure for the body control module. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.
  2. Replace the body control module. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 15

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13

Replace the instrument panel cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.

Did you complete the replacement?

Go to Step 15

--

14

Replace the liftgate lock actuator/ajar switch. Refer to Liftgate Wedge Replacement .

Did you complete the replacement?

Go to Step 15

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15

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2