• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
B+ | 1 | 1 | -- | -- |
Ignition | 1 | 1 | -- | -- |
Sunroof Switch Close Signal | 1 | 1 | 1* | -- |
Sunroof Switch Close Vent Signal | 1 | 1 | 1* | -- |
Sunroof Switch Express Signal | 1 | 2 | 1* | -- |
Sunroof Switch Express Vent Signal | 1 | 2 | 1* | -- |
Sunroof Switch Open Signal | 1 | 1 | 1* | -- |
Sunroof Switch Open Vent Signal | 1 | 1 | 1* | -- |
Ground - Sunroof Switch | -- | 1 | -- | -- |
Ground - Sunroof Motor/Actuator | -- | 1 | -- | -- |
* Internal damage to the sunroof switch may occur if shorted to B+ 1. Power sunroof malfunction 2. Power sunroof express feature malfunction |
The sunroof module determines the sunroof motor direction based on inputs received from the overhead console sunroof switches. The module supplies each of the sunroof switch signal circuits with a 12-volt reference. When the switch is pressed the signal circuit is pulled low signaling the roof open or closed request. When the ignition switch is in the ON position or when retained accessory power (RAP) is active, voltage is applied to the sunroof module via the RAP relay and the S/ROOF fuse. For a description and operation of the RAP system, refer to Retained Accessory Power (RAP) Description and Operation . The sunroof module controls the sunroof motor direction by changing the polarity of the applied voltage. The sunroof module remembers the sunroof position whenever the ignition switch is turned to the OFF position. The limit switch is used as an input to the sunroof module to indicate that the glass is fully closed, or in the soft stop positions. The limit switch is grounded only when the sunroof glass is in the fully closed or soft stop positions, otherwise it is open.
If the sunroof is experiencing an intermittent inoperative condition, check the sunroof switch ground circuit for an open. If the sunroof switch ground circuit is open, the switch may take a redundant path to ground through the switch illumination circuit. When the lights are turned On, the redundant path to ground is removed, and the sunroof will become inoperative.
A short to B+ on any of the sunroof switch signal circuits will open the ground trace in the sunroof switch.
⇒ | If greater than 10 ohms, test the ground circuit for an open/high resistance. |
• | Terminal 8 sunroof switch open signal |
• | Terminal 2 sunroof switch close signal |
• | Terminal 4 sunroof switch open vent signal |
• | Terminal 6 sunroof switch close vent signal |
⇒ | If the roof moved in all directions, replace the sunroof switch. |
⇒ | If greater than 1 ohm, test the ground circuit for an open/high resistance. |
⇒ | If greater than 1 ohm, test the ground circuit for an open/high resistance. |
⇒ | If the test lamp does not illuminate, test the battery positive voltage circuit for a short to ground or an open/high resistance |
⇒ | If the test lamp does not illuminate, test the accessory voltage circuit for a short to ground or an open/high resistance |
• | Terminal 1 sunroof express vent signal |
• | Terminal 2 sunroof switch close signal |
• | Terminal 4 sunroof switch open vent signal |
• | Terminal 6 sunroof switch close vent signal |
• | Terminal 7 sunroof express signal |
• | Terminal 8 sunroof switch open signal |
⇒ | If less than the specified value, test the appropriate signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the sunroof motor/actuator assembly. |
⇒ | If the roof did not express open, test the express signal circuit for a short to voltage or an open high resistance. If the circuit tests normal, replace the sunroof motor/actuator assembly. |
⇒ | If the roof did not express vent open, test the express signal circuit for a short to voltage or an open high resistance. If the circuit tests normal, replace the sunroof motor/actuator assembly. |
• | Switch low reference terminal 5 and roof open terminal 8 |
• | Switch low reference terminal 5 and roof express terminal 7 |
• | Switch low reference terminal 5 and roof close terminal 2 |
• | Switch low reference terminal 5 and vent open terminal 4 |
• | Switch low reference terminal 5 and vent express terminal 1 |
• | Switch low reference terminal 5 and vent close terminal 6 |
⇒ | If less than infinite for any test, replace the sunroof switch. |
Important: If the switch tests open in any switch position other than Off, test the sunroof switch signal circuits for a short to voltage before replacing the switch.
• | Switch low reference terminal 5 and roof open terminal 8 |
• | Switch low reference terminal 5 and roof express terminal 7 |
• | Switch low reference terminal 5 and roof close terminal 2 |
• | Switch low reference terminal 5 and vent open terminal 4 |
• | Switch low reference terminal 5 and vent express terminal 1 |
• | Switch low reference terminal 5 and vent close terminal 6 |
⇒ | If greater than 3 ohms on any of the tests, replace the sunroof switch. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for sunroof motor/actuator replacement, programming, and setup |