Sunroof by-passing closed position
 

Hello Everyone,

Just purchased a 03 ZR2 Blazer. I noticed the sunroof is not stopping in the closed position. I searched through the owners manual and could not find one reference to sunroof operation but managed to find some info online. If I push and release the toggle switch to the rear, the roof opens and stops at the halfway position. Will not open all the way. If I push and hold the toggle in the forward position the sunroof will open to the vent position. If I push the toggle to the rear to close the sunroof, the roof will again open to the halfway position. I obviously have an issue going on. The sunroof is not stopping in the closed position at all or opening all the way. Motor sounds good, no clicking and/or binding. Sunroof slides w/out issue. Tracks look fine and nothing appears to be broken. In searching the net, I have found posts concerning re-calibration of the sunroof module and drive motor timing. I don't know how correct this info is. Also found a reference to a GM# 12333707 sunroof module as being faulty. Can these modules be tested at all?? Any assistance would be greatly appreciated. Thank you all for your time.

Regards,
Rob