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Volkswagen Passat W8 Car Problems

Water From Clogged Sun Roof Drains May Damage Control Modules on Volkswagen Passat W8

Problem Description and Solution

Clogged sunroof drains can allow water to enter the interior and accumulate under the carpet where various control modules are mounted. Over time, the accumulated moisture can damage the control modules.

(14 people reported this problem)

Problem Data

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Average mileage: 115,694 (46,000–190,921)
3 model years affected: 2002, 2003, 2004

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Viewing 1-10 of 10 comments
I had this problem too. Make sure your service station cleans the weep holes and tubing that discharge the water from the sun roof gasket to the street every time you get the oil changed (dealerships seem to do it as part of the standard oil change service). I have covered the gap between the sun roof and car top with clear duck tape to keep water from getting to the gasket.

I was lucky because my insurance covered $1,900 of the cost of the repair and replacement of the comfort control module that was shorted out. Most of the cost was for labor because the front seats and most of the passenger cabin has to be removed to get to the module.
Noticed the interior floor was flooding every time it rained. After taking it to several repair shops then having it checked at a windshield replacing shop. Luckily the worker was able to find the actual problem which was the sunroof drain was clogged causing the water to build up and spread throughout the car, mostly the carpet on the floor and glove compartment. In the winter time, anything electric (i.e. radio, odometer, dashboard lights etc.) will shut off while driving. Assuming that the water is freezing up and is damaging the control modules. Still working on fixing the trouble & replacing all damaged parts.
CCM (comfort control module) has built up corrosion around harness that enters it due to moisture from the sun roof. this being said the CCM has coded at failure causing my 2 rear doors to be locked and unusable and also the windows to be unusable. Also having issues with a code saying failure towards my oil pressure causing my car to not start. 2 problems in less than a month.
Sunroof drains clogged and water accumulated on floor of passenger seat. This shorted out the TCM which now needs replaced (2000.00 at the dealership).
We have water that comes up on the passenger side under the floor mat...We have pulled the carpet up and got out all the water but we've noticed the water coming back... we are not driving this car at the time.. Dealer says he doesn't know of a recall on this model.
The Florida heat caused the drainage lines to melt closed and the water backed up into the car. My floor was wet for a few days before I realized it. I have had electrical problems ever since.