GM Service Manual Online
For 1990-2009 cars only

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step will test for an intermittent condition when testing if the sunroof will slide and soft stop at the vent position. If the sunroof operates properly to the full vent position, then inspect the sunroof limit switch LS1 for a stuck switch causing an intermittent short to ground.

  2. Testing for a short to ground in the sunroof limit switch LS1 circuit or a stuck or closed limit switch.

Step

Action

Value(s)

Yes

No

Schematic Reference: Sunroof Schematics

DEFINITION: Sunroof will slide to vent position, but it will not stop at the soft stop at the vent position. As the glass slides past the soft stop vent position the glass tends to shift out of alignment.

1

Did you perform A Diagnostic System Check - Power Sunroof?

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Go to Step 2

Go to Diagnostic System Check - Power Sunroof

2

Operate the power sunroof to the vent position.

Does the system operate normally?

--

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

Go to Step 3

3

  1. Disconnect the sunroof opening position switch harness connector.
  2. Turn the ignition ON, with the engine OFF.
  3. Measure the reference voltage between the sunroof limit switch LS1 circuit at the sunroof opening position switch harness connector to a good ground.

Does the voltage measure near the specified value?

4.5-5.5 V

Go to Step 5

Go to Step 4

4

Test the sunroof limit switch LS1 circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 7

Go to Step 6

5

Replace the sunroof opening position switch harness connector. Refer to Sunroof Position Encoding System Switch Replacement .

Did you complete the replacement?

--

Go to Step 7

--

6

Replace the sunroof module. Refer to Power Sunroof Module Replacement .

Did you complete the replacement?

--

Go to Step 7

--

7

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3