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 - Body Rear End?

Go to Step 2

Go to Symptoms - Body Rear End

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF, car in PARK.
  3. With a scan tool, view the trunk release output parameter in the remote function actuator (RFA).
  4. With a scan tool, command the trunk release ON and OFF.

Does the parameter change state?

Go to Step 3

Go to Step 22

3

Does the rear compartment lid release operate?

Go to Step 4

Go to Step 9

4

  1. With a scan tool, view the trunk release switch parameter in the body control module (BCM).
  2. Press the trunk release switch.

Does the parameter change state?

Go to Step 7

Go to Step 5

5

  1. Disconnect the rear compartment lid release switch.
  2. Connect a fused jumper between the battery positive voltage supply circuit of the trunk release switch and the ground circuit of the trunk release switch.
  3. View the trunk release switch parameter.

Does the parameter change state?

Go to Step 21

Go to Step 6

6

  1. Connect a fused jumper between the battery positive voltage supply circuit of the trunk release switch and a good ground.
  2. View the trunk release switch parameter.

Does the parameter change state?

Go to Step 17

Go to Step 18

7

  1. Remove the trunk release relay.
  2. Disconnect the trunk release actuator.
  3. Install a fused jumper wire between the battery positive voltage circuit of the trunk release relay and the trunk release actuator supply circuit of the trunk release relay.
  4. Connect a test lamp between supply circuit of the trunk release actuator and the ground circuit of the trunk release actuator.

Does the test lamp illuminate?

Go to Step 20

Go to Step 8

8

Connect a test lamp between the supply circuit of the trunk release actuator and a good ground.

Does the test lamp illuminate?

Go to Step 16

Go to Step 15

9

  1. Remove trunk release relay.
  2. Connect a test lamp between the battery positive voltage circuit of the trunk release relay and a good ground.

Does the test lamp illuminate?

Go to Step 10

Go to Step 14

10

  1. Connect a test lamp between the battery positive voltage circuit of the trunk release relay and the control circuit of the rear compartment lid release relay.
  2. Press the Trunk Release button.

Does the test lamp turn ON and OFF with each command?

Go to Step 19

Go to Step 11

11

Did the test lamp remain illuminated with each command?

Go to Step 13

Go to Step 12

12

Test the control circuit of the trunk release relay for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 29

Go to Step 22

13

Test the control circuit of the trunk release relay for a short to ground. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 29

Go to Step 22

14

Repair high resistance or open in the control circuit of the trunk release relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 29

--

15

Repair the high resistance or open in the control circuit of the trunk release actuator. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 29

--

16

Repair the high resistance or open in the ground circuit of the trunk release actuator. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 29

--

17

Repair the high resistance or open in the ground circuit of the trunk release switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 29

--

18

Test the control circuit of the trunk release switch for a high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find or correct the condition?

Go to Step 29

Go to Step 23

19

Inspect for poor connections at the trunk release relay. 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 29

Go to Step 24

20

Inspect for poor connections at the trunk release actuator. 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 29

Go to Step 25

21

Inspect for poor connection at the harness connector of the trunk release 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 29

Go to Step 26

22

Inspect for poor connection at the harness connector of the RFA. 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 29

Go to Step 27

23

Inspect for poor connection 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 29

Go to Step 28

24

Replace the trunk release relay.

Did you complete the replacement?

Go to Step 29

--

25

Replace the trunk release actuator.

Did you complete the replacement?

Go to Step 29

--

26

Replace the trunk release switch.

Did you complete the replacement?

Go to Step 29

--

27

Replace the RFA.

Did you complete the replacement?

Go to Step 29

--

28

Important: When replacing the BCM refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 29

--

29

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2