GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Instrument Cluster Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console

2

Did you review the release system operation and perform the necessary inspections?

--

Go to Step 3

Go to Symptoms

3

Verify that the gate ajar indicator is inoperative.

Does the gate ajar indicator operate normally?

--

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

Go to Step 4

4

  1. Using the scan tool, select Instrument Panel Cluster.
  2. Select Data Display.
  3. Select OUTPUTS.

Does the REAR GATE/DOOR output indicate CLOSED with the liftglass or liftgate open?

--

Go to Step 5

Go to Step 17

5

  1. Using the scan tool, select Body Control Module.
  2. Select Data Display.
  3. Select Data List.
  4. Select INPUT 1.

Does the REAR GATE/DOOR output indicate CLOSED with the liftglass or liftgate open?

--

Go to Step 6

Go to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console or Diagnostic System Check - Body Control System in Body Control System

6

Is the vehicle equipped with a lift gate?

--

Go to Step 7

Go to Step 8

7

Is the tail gate alarm indicator only inoperative with the liftgate open?

--

Go to Step 10

Go to Step 8

8

  1. Disconnect the rear window wiper cutout and liftglass ajar jamb switch connector.
  2. Connect a 10A fused jumper lead from terminal A of the rear window wiper cutout and liftglass ajar jamb switch connector and ground. Refer to Circuit Testing in wiring systems.
  3. Turn the ignition switch to the RUN position.

Did the tail gate alarm indicator illuminate?

--

Go to Step 9

Go to Step 12

9

  1. Connect the 10A fused jumper lead between terminal A and terminal B of the rear window wiper cutout and liftglass ajar jamb switch connector. Refer to Circuit Testing in wiring systems.
  2. Turn the ignition switch to the RUN position.

Did the tail gate alarm indicator illuminate?

--

Go to Step 15

Go to Step 14

10

  1. Disconnect the liftgate ajar jamb switch connector.
  2. Connect a 10A fused jumper lead from terminal B of the liftgate ajar jamb switch connector and ground. Refer to Circuit Testing in wiring systems.
  3. Turn the ignition switch to the RUN position.

Did the tail gate alarm indicator illuminate?

--

Go to Step 13

Go to Step 11

11

  1. Connect the 10A fused jumper lead between terminal B and terminal D of the liftgate ajar jamb switch connector. Refer to Circuit Testing in wiring systems.
  2. Turn the ignition switch to the RUN position.

Did the tail gate alarm indicator illuminate?

--

Go to Step 16

Go to Step 14

12

Locate and repair the open or the high resistance in CKT 1303 between the rear window wiper cutout and liftglass ajar jamb switch and the BCM. Refer to Circuit Testing and Wiring Repairs in Wiring

Was an open found and repaired?

--

Go to Step 19

Go to Step 18

13

Locate and repair the open or the high resistance in CKT 1303 between the liftgate ajar jamb switch and S900. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 19

--

14

Locate and repair the open or the high resistance in CKT 1350 (BLK). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

--

Go to Step 19

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15

Replace the rear window wiper cutout and liftglass ajar jamb switch.

Is the repair complete?

--

Go to Step 19

--

16

Replace the liftgate ajar jamb switch.

Is the repair complete?

--

Go to Step 19

--

17

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

Is the repair complete?

--

Go to Step 19

--

18

  1. Replace the BCM. Refer to Body Control Module Replacement in Body Control System.
  2. Reconnect all of the disconnected components.
  3. Program the BCM with the proper calibrations.
  4. Perform the Passlockā„¢ Learn Procedure using the scan tool.
  5. Using the scan tool, clear all of the DTCs.

Is the repair complete?

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Go to Step 19

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19

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 4