GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Schematic Reference: Sunroof Schematics

DEFINITION: The sunroof glass will bypass the flush closed position when sliding from vent position.

1

Did you review the Power Sunroof Description and Operation?

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Go to Step 2

Go to Diagnostic System Check - Power Sunroof

2

Operate the power sunroof system.

Does the system operate normally?

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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. Measure the reference voltage of the sunroof limit switch LS2 circuit at the sunroof opening position switch harness connector.

Does the reference voltage measure near the specified value?

4.5-5.5 V

Go to Step 4

Go to Step 5

4

Measure the reference voltage of the sunroof limit switch LS3 circuit at the sunroof opening position switch harness connector.

Does the reference voltage measure near the specified value?

4.5-5.5 V

Go to Step 7

Go to Step 6

5

Test the sunroof limit switch LS2 circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 8

6

Test the sunroof limit switch LS3 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 11

Go to Step 9

7

Inspect for a poor connection at the sunroof limit 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 11

Go to Step 9

8

Inspect for a poor connection at the sunroof module harness connector. 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 11

Go to Step 10

9

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

Did you complete the replacement?

--

Go to Step 11

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10

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

Did you complete the replacement?

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Go to Step 11

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11

  1. Reconnect all disconnected connectors.
  2. Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2