Drive Unit

Drive Mechanism Defective

Repair instruction for defective drive mechanism
Grating or clicking noise from the drive unit.

Repair instruction
If the gear of the drive unit is damaged, see Fig. 1, or the motor pinion is damaged, check the slide/tilt sunroof mechanism for the following causes:
1. Corrosion on guide pipes, traction cables and drive unit, which leads to sluggish movement and blockages. See Fig. 2 and Fig. 3.
2. Guide pipes that have come loose and blockages this causes. See Fig. 4.
3. Damaged or squashed drive cable
4. Blockages elsewhere, possibly caused by foreign bodies.

If the cause of the defective drive unit is corrosion or a loose guide pipe or a damaged drive cable, the roof frame and the drive unit must be replaced. The glass panels can be reused.

If the panorama sunroof is blocked elsewhere, locate the blockage and remove it.

Important notes
If no damage is found on the gear of the drive unit, do not operate the panorama sunroof. First replace the roof frame and then initialize the sliding/tilting sunroof module. The glass panels can be reused.

Corrosion on the guide pipe can only occur in the case of vehicles up to date of manufacture January 2007. As of date of manufacture 04/2007, stainless steel guides are fitted; the problem no longer occurs.

Image 1
Damaged gear of the drive mechanism.







Fig. 2
If the corrosion is more advanced, it can be detected from outside. Check the guide pipes and traction cables for corrosion.







Image 3
Corrosion on the components when removed.







Image 4
The guide pipe has come loose from the guide rail.