What causes sunroof to retract open, but when closing it won't

Hi my name is XXXXX XXXXX to just answer.

These sunroofs can be a bit troublesome at times. Making sure the tracks are clean of all debris , is a good start. ( thats the #1 cause for inoperative sun roof) Clean the weather strips to with mild soap and water.( do not remove the grease on the tracks)

There is an synchronization process that may need to be performed. here is the process to reinitialize the sunroof. If this doesn't work there are are some other things that can be checked.

In the event that one of the following conditions occur, perform the reinitialization procedure listed below prior to following SI for diagnosis.

Synchronization will be necessary any time the sunroof motor is removed from the unit. The sunroof module is synchronized when the motor controller learns the full vent position.

To synchronize the sunroof:

(Please read directions completely prior to beginning the procedure)

1. Turn ON the ignition with the engine OFF.
2. . DO NOT OPERATE THE SUNROOF GLASS IN THE OPEN/TILT DOWN DIRECTION UNTIL THE INITIALIZATION PROCEDURE IS COMPLETE OR SERIOUS DAMAGE MAY OCCUR.
3. Using the close/tilt up portion of the sunroof switch, operate the sunroof glass until it reaches the full vent position. Even if the sunroof stops early, proceed to step 4.
4. Continue to hold the close/tilt up portion of the sunroof switch for at least 30 seconds or until you hear a slight click from the front of the sunroof mechanism.
5. The slight clicking noise at the front of the sunroof confirms the initialization is complete.
6. Verify that the system operates normally.

Once the synchronization is complete, the position of the motor and mechanism is stored in the memory of the sunroof motor controller. The motor controller retains this memory even if power is disconnected to the motor.

If reinitialization does not correct the concern, perform the following steps:

1. Reference SI and use the R&R procedure for removing the complete sunroof module assembly.
2. Remove the motor from the unit and force the Pin Guides forward until the hard stop is reached. If water channel guides are out of track, there may resistance to moving pin guides forward. If water channel guides are out of track you will need to feed them through the rear of track. Make sure both sides are in complete forward position. In the event track mechanism components are damaged, use Service Kit P/N 88979948. Reference SI Document ID #1364848 for replacement procedure.
3. Once the track mechanism is repaired, reattach the motor and follow the reinitialization procedure listed above.
4. Check for proper operation.