AudiWorld Forums - 2006 a4 Electrical DISASTER

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2006 a4 Electrical DISASTER

2006 a4 Quattro 2.0T with a major electrical problem
Here’s a list of my problems:

-No functioning windows/sunroof, and interior auto locks only occasionally work, but all buttons and knobs illuminate
-No interior dome lights work although when I open the trunk and rest it down without locking it, they work intermittently.
-EPC lights occasionally comes on but only after putting a lot of miles in a short time, causing it not to shift properly or shift above 4th gear and the RPMs significantly increase. It either starts up with the EPC light on or it comes on while driving. When it comes on while driving and I have the cruise set it disables the cruise, shifts down to 4th and revs up. Have found if I flip the cruise switch to off and shut off/restart car that the light goes off and runs normal (hit or miss how long it takes before I can turn on cruise control without EPC light coming right back on).

Appreciate the help in advance and let me know if you know how to get a cheap wiring diagram

The first 2 point to the comfort module which is under the driver's seat and susceptible to water damage if you drains in the sunroof and ECU areas aren't working properly.

EPC could be any number of things. You didn't mention that the car runs poorly, just the shifting issue. I suspect it is related to the comfort module as that controls cruise control functions. I would download codes from a VAGCOM reader and go from there.