GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

B+

1

1

--

--

Sunroof Enable Signal

1

1

1

--

Sunroof Switch Data 1 Signal

1

1

1

--

Sunroof Switch Data 2 Signal

1

1

1

--

Sunroof Switch Data 3 Signal

1

1

1

--

Sunroof Switch Data 4 Signal

1

1

1

--

Sunroof Switch Data 5 Signal

1

1

1

--

Sunroof Switch Data 6 Signal

1

1

1

--

Sunroof Switch Low Reference

--

1

--

--

Sunroof Module Ground

--

1

--

--

1. Power sunroof inoperative

Circuit/System Description

Battery positive voltage is supplied at all times to the sunroof control module from the SUNROOF MOD 30A fuse located in the right rear fuse block. With the ignition in the ON or ACCESSORY positions, the sunroof enable signal circuit is pulled low by the rear integration module (RIM) allowing for sunroof operation. Once the ignition switch is turned to OFF, the sunroof will continue to operate until any door is opened or when the Retained Accessory Power (RAP) has timed out. For a complete description of RAP operation, refer to Retained Accessory Power (RAP) Description and Operation . Ground for the sunroof control module is supplied from G402.

The power sunroof is operated from the sunroof switch that is located in the over head console. The sunroof switch, when rotated to a selection, will send coded information to the sunroof module as to what position the sunroof window is to open to. The sunroof module will command the motor to open the sunroof glass to the requested position.

Diagnostic Aids

    • The sunroof control module is also referenced as the sunroof motor/actuator.
    • The sunroof motor and sunroof module are integral parts of an assembly and are not serviced separately.

Reference Information

Schematic Reference

Sunroof Schematics

Connector End View Reference

Sunroof Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Circuit/System Testing

Important: Portions of the circuit/system testing require removal of the headliner. It is suggested that the sunroof switch component test is performed prior to the removing the headliner.

  1. Ignition OFF, disconnect the harness connector at the sunroof switch.
  2. Interior lamps OFF, test for less than 5 ohms of resistance between the ground circuit terminal 7 and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Disconnect the inline harness connector C401.
  5. Test for less than 1 ohm of resistance between the ground circuit terminal A and ground.
  6. If greater than the specified range, test the ground circuit for an open/high resistance.
  7. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal C and ground.
  8. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance
  9. Ignition ON, verify that a test lamp illuminates between the signal circuit terminal B and B+.
  10. If the test lamp does not illuminate, test the signal circuit for a short to battery or an open/high resistance. If the circuit tests normal, refer to Retained Accessory Power (RAP) Inoperative .
  11. Ignition OFF, connect the inline harness connector C401.
  12. Disconnect the harness connector at the sunroof module.
  13. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit terminal 4 and ground.
  14. If greater than the specified range, test the ground circuit for an open/high resistance.
  15. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.
  16. If the test lamp does not illuminate, test the B+ circuit for an open/high resistance
  17. Ignition ON, verify that a test lamp illuminates between the signal circuit terminal 2 and B+.
  18. If the test lamp does not illuminate, test the signal circuit for a short to battery or an open/high resistance.
  19. Ignition OFF, connect the harness connector at the sunroof control module.
  20. Ignition ON, at the sunroof switch, test for B+ between the signal circuits listed below and ground.
  21. • Sunroof switch terminal 8
    • Sunroof switch terminal 9
    • Sunroof switch terminal 10
    • Sunroof switch terminal 11
    • Sunroof switch terminal 12
    • Sunroof switch terminal 13
    If less than the specified range, test the appropriate signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the sunroof control module.
  22. If all circuits test normal, test or replace the sunroof switch.

Component Testing

Sunroof Switch

  1. Ignition OFF, disconnect the harness connector at the sunroof switch.
  2. Test for continuity between the pins indicated for each position of the switch. The continuity should display as indicated in the test table.
  3. If not the specified value for all switch positions, test the appropriate signal circuit for a short to battery voltage. If all circuits test normal, replace the sunroof switch.

Switch Position

Pin 7 & Pin 8

Pin 7 & Pin 9

Pin 7 & Pin 10

Pin 7 & Pin 11

Pin 7 & Pin 12

Vent Position 3

0-200 ohms

Infinite

0-200 ohms

Infinite

Infinite

Vent Position 2

Infinite

Infinite

0-200 ohms

Infinite

Infinite

Vent Position 1

Infinite

Infinite

0-200 ohms

0-200 ohms

Infinite

Not Used

0-200 ohms

0-200 ohms

0-200 ohms

0-200 ohms

Infinite

Close

0-200 ohms

0-200 ohms

0-200 ohms

0-200 ohms

Infinite

Not Used

Infinite

0-200 ohms

0-200 ohms

0-200 ohms

Infinite

Roof Position 1

Infinite

0-200 ohms

Infinite

0-200 ohms

Infinite

Roof Position 2

0-200 ohms

Infinite

Infinite

0-200 ohms

Infinite

Roof Position 3

0-200 ohms

Infinite

Infinite

0-200 ohms

Infinite

Roof Position 4

Infinite

Infinite

Infinite

0-200 ohms

Infinite

Roof Position 5

Infinite

Infinite

Infinite

0-200 ohms

0-200 ohms

Roof Position 6

0-200 ohms

Infinite

Infinite

0-200 ohms

0-200 ohms

Roof Position 7

0-200 ohms

0-200 ohms

Infinite

0-200 ohms

0-200 ohms

Roof Position 8

Infinite

0-200 ohms

Infinite

0-200 ohms

0-200 ohms

Roof Position 9

Infinite

0-200 ohms

0-200 ohms

0-200 ohms

0-200 ohms

Roof Position 10

0-200 ohms

0-200 ohms

0-200 ohms

0-200 ohms

0-200 ohms

Roof Position 11

0-200 ohms

Infinite

0-200 ohms

0-200 ohms

0-200 ohms

Roof Position 12

Infinite

Infinite

0-200 ohms

0-200 ohms

0-200 ohms

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Sunroof Switch Replacement
    •  Control Module References for sunroof motor/actuator replacement, programming, and setup