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

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Verify that the midgate power window is inoperative.

Does the midgate power window operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the overhead console switch assembly electrical connector A.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the retained accessory power (RAP) supply voltage circuit of the overhead console switch assembly electrical connector A with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Retained Accessory Power (RAP) Inoperative

4

  1. Turn OFF the ignition.
  2. Connect the overhead console switch assembly electrical connector A.
  3. Disconnect the midgate glass motor electrical connector.
  4. Turn ON the ignition, with the engine OFF.
  5. Probe the battery positive voltage circuit of the midgate glass motor electrical connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 22

5

  1. Probe the midgate overhead console switch down signal circuit of the midgate glass motor electrical connector with a test lamp that is connected to a good ground.
  2. Activate the midgate window switch to the DOWN position.

Does the test lamp illuminate?

Go to Step 6

Go to Step 13

6

  1. Probe the midgate overhead console switch up signal circuit of the midgate glass motor electrical connector with a test lamp that is connected to a good ground.
  2. Activate the midgate window switch to the UP position.

Does the test lamp illuminate?

Go to Step 7

Go to Step 14

7

Probe the ground circuits of the midgate glass motor electrical connector with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

Go to Step 8

Go to Step 23

8

Probe the midgate ajar switch signal circuit of the midgate glass motor electrical connector with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

Go to Step 17

Go to Step 9

9

  1. Turn OFF the ignition.
  2. Disconnect the right midgate latch electrical connector.
  3. Probe the ground circuit of the right midgate latch electrical connector with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

Go to Step 10

Go to Step 23

10

  1. Connect the midgate glass motor electrical connector.
  2. Turn ON the ignition, with the engine OFF.
  3. Probe the midgate ajar switch signal circuit of the right midgate latch electrical connector with a test lamp that is connected to a good ground.
  4. Activate the midgate window switch to the UP position.

Does the test lamp illuminate?

Go to Step 18

Go to Step 11

11

  1. Turn OFF the ignition.
  2. Connect the right midgate latch electrical connector.
  3. Disconnect the body control module (BCM) electrical connector C2.
  4. Disconnect the left midgate latch electrical connector.
  5. Turn ON the ignition, with the engine OFF.
  6. Probe the midgate ajar indicator signal circuit of the left midgate latch electrical connector with a test lamp that is connected to a good ground.
  7. Activate the midgate window switch to the UP position.

Does the test lamp illuminate?

Go to Step 15

Go to Step 12

12

  1. Turn OFF the ignition.
  2. Connect the left midgate latch electrical connector.
  3. Connect the BCM electrical connector C2.
  4. Disconnect the inline diode electrical connector.
  5. Turn ON the ignition, with the engine OFF.
  6. Probe the midgate ajar switch signal circuit of the inline diode electrical connector with a test lamp that is connected to a good ground.
  7. Activate the midgate window switch to the UP position.

Does the test lamp illuminate?

Go to Step 16

Go to Step 24

13

Test the midgate overhead console switch down signal circuit for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 19

14

Test the midgate overhead console switch up signal circuit for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 19

15

Test the midgate ajar switch signal circuit for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 20

16

Test the midgate ajar indicator signal circuit for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 21

17

Inspect for poor connections at the harness connector of the midgate glass motor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 25

18

Inspect for poor connections at the harness connector of the right midgate latch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 26

19

Inspect for poor connections at the harness connector of the midgate overhead console switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 27

20

Inspect for poor connections at the harness connector of the left midgate latch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 28

21

Inspect for poor connections at the harness connector of the inline diode. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 29

22

Repair the open or short to ground in the battery positive voltage circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 30

--

23

Repair the open in the appropriate ground circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 30

--

24

Repair the open or short to ground in the midgate ajar switch signal circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 30

--

25

Replace the midgate glass motor. Refer to Midgate Window Regulator Replacement .

Did you complete the replacement?

Go to Step 30

--

26

Replace the right midgate latch. Refer to Midgate Latch Replacement .

Did you complete the replacement?

Go to Step 30

--

27

Replace the midgate overhead console switch. Refer to Endgate Window, Midgate Window, and Rear Moveable Roof Switch Assembly Replacement - Overhead Console .

Did you complete the replacement?

Go to Step 30

--

28

Replace the left midgate latch. Refer to Midgate Latch Replacement .

Did you complete the replacement?

Go to Step 30

--

29

Replace the inline diode. Refer to Folding Rear Panel Harness Replacement .

Did you complete the replacement?

Go to Step 30

--

30

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2