GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Body Rear End Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn the ignition ON.
  2. Open the cargo doors, liftgate or liftglass.

Is the cargo door ajar message displayed?

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

Go to Step 3

3

  1. Install a scan tool.
  2. Observe the Cargo Door Agar Switch parameter in the BCM Inputs data list.

Does the scan tool display the switch parameter as Open?

Go to Step 9

Go to Step 4

4

  1. Disconnect the body harness to liftgate harness inline connector C901, or the body harness to cargo door contact plate connectors.
  2. Using a fused jumper wire ground the liftgate ajar switch signal circuit in the body harness connector.

Does the scan tool display the switch as Open?

Go to Step 5

Go to Step 6

5

Test the liftgate ajar switch signal and ground circuits in the liftgate or cargo door harnesses for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 7

6

Test the liftgate ajar switch signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 8

7

Inspect for poor connections at the cargo door or liftgate ajar switches. 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 13

Go to Step 10

8

Inspect for poor connections at the harness connector of the BCM. 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 13

Go to Step 11

9

Inspect for poor connections at the harness connector of the instrument panel cluster (IPC). 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 13

Go to Step 12

10

Replace the malfunctioning door ajar switch. Refer to Liftgate Latch Replacement or Door Latch Replacement .

Did you complete the replacement?

Go to Step 13

--

11

Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 13

--

12

Replace the IPC. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 13

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13

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3