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 the if the sunroof will slide to the open position. If it opens, then inspect the sunroof limit switch LS2 for a stuck switch causing an intermittent short to ground.

  2. Testing for a short to ground in the sunroof limit switch LS2 circuit or a stuck or closed limit switch.

Step

Action

Value(s)

Yes

No

Schematic Reference: Sunroof Schematics

DEFINITION: Sunroof only slides between the closed and vent positions, does not open.

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 open position.

Does the system operate normally?

--

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

Go to Step 3

3

  1. Turn the ignition ON, with the engine OFF.
  2. Activate the sunroof switch to close the sunroof.
  3. Measure the voltage between the sunroof limit switch LS2 circuit and the sunroof limit switch low reference circuit at the sunroof module harness connector.

Does the voltage measure near the specified value?

4.5-5.5 V

Go to Step 6

Go to Step 4

4

  1. Disconnect the sunroof opening position switch harness connector.
  2. Test the sunroof limit switch LS2 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 5

5

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

Did you complete the replacement?

--

Go to Step 7

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6

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

Did you complete the replacement?

--

Go to Step 7

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7

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3