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

Sunshade Module B+

1

1

--

--

Front Overhead Console Courtesy/Reading Lamps B+

2

2

--

--

Backup Lamp Signal

1

1

1

--

Sunshade Switch Signal

2

2

2

--

Rear Window Sunshade Motor Control

1

1

1

--

Sunshade Module Ground

--

1

1

--

1. Rear Window Sunshade Malfunction

2. Sunshade Switch Malfunction

Circuit/System Description

The sunshade module contains the logic for extending or retracting the sunshade based on inputs received from the sunshade switch. The switch is a momentary type, and is located in the front overhead console courtesy/reading lamps. The module activates the sunshade motor based on the inputs received from the switch. When the Ignition switch is in the ON position, Accessory position, or when retained accessory power (RAP) is active (key off), voltage is applied to the power sunshade control module via the RAP relay. The sunshade control module controls the sunshade motor direction by changing the polarity of the applied voltage. If the ignition switch is turned to the OFF position while the sunshade is moving, the module enters a "Standby" mode, and the shade will complete its cycle. The module will remain in the "Standby" mode and the shade will remain in the position it was in when movement ceased, until the module receives another switch activation input. Movement will then resume, but in the opposite direction from the last activation.

The sunshade motor assembly contains the reversible DC drive motor and the gear train used to move the shade material to the desired position. The motor also contains a positive temperature coefficient (PTC) thermal circuit breaker to protect the system from an overload.

Reference Information

Schematic Reference

Moveable Window Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

23710

Electrical Information Reference

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

Circuit/System Verification

Ignition ON, transaxle in P (park), command the rear window sunshade to EXTEND and RETRACT by pressing the sunshade switch. The rear window sunshade should EXTEND and RETRACT each time the sunshade switch is pressed.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the front overhead console courtesy/reading lamps.
  2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 3 and ground.
  3. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  4. Ignition OFF, connect the harness connector at the front overhead console courtesy/reading lamps and disconnect the X1 harness connector at the sunshade module.
  5. Test for less than 1 Ω between the ground circuit terminal 2 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 1 and ground.
  8. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance, if the circuit tests normal, and the B+ circuit fuse is open, replace the sunshade module.
  9. Connect a test lamp between the signal circuit terminal 4 and ground.
  10. Command the rear window sunshade motor to EXTEND and RETRACT by pressing the sunshade switch, the test lamp should illuminate each time the sunshade switch is pressed.
  11. If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the front overhead console courtesy/reading lamps.
    If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal, test or replace the front overhead console courtesy/reading lamps.
  12. With the transaxle in P (park), verify that test lamp does not illuminate between the signal circuit terminal 6 and ground.
  13. If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, refer to Backup Lamps Malfunction.
  14. With the transaxle in R (reverse), verify that a test lamp illuminates between the signal circuit terminal 6 and ground.
  15. If the test lamp does not illuminate, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, refer to Backup Lamps Malfunction.
  16. Ignition OFF, connect the X1 harness connector at the sunshade module and disconnect the harness connector at the rear window sunshade motor.
  17. Connect a test lamp between the control terminal 1 and the control terminal 2.
  18. Ignition ON, command the rear window sunshade motor to EXTEND and RETRACT by pressing the sunshade switch. The test lamp should illuminate when commanding the EXTEND and RETRACT states.
  19. If the test lamp is always ON, test either control circuit for a short to voltage. If the circuits test normal, replace the sunshade module.
    If the test lamp does not illuminate during either command, test either control circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the sunshade module.
  20. If all circuits tests normal, test or replace the rear window sunshade motor.

Component Testing

Sunshade Switch

  1. Ignition OFF, disconnect the harness connector at the front overhead console courtesy/reading lamps.
  2. Test for infinite resistance between the signal terminal 5 and the B+ terminal 3 with the switch in the open position.
  3. If not the specified value, replace the front overhead console courtesy/reading lamps.
  4. Test for less than 2 Ω between the signal terminal 5 and the B+ terminal 3 with the switch in the closed position.
  5. If greater than the specified range, replace the front overhead console courtesy/reading lamps.

Rear Window Sunshade Motor

  1. Ignition OFF, disconnect the harness connector at the rear window sunshade motor.
  2. Install a 10A fused jumper wire between one of the control terminals and 12V. Momentarily install a jumper wire between the other control terminal and ground. Reverse the jumper wires at least two times, the rear window sunshade motor should perform the EXTEND/RETRACT functions.
  3. If it does not perform as specified, replace the rear window sunshade motor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Roof Console Replacement
    •  Rear Window Shelf Trim Panel Replacement