Clearing CEL Code causing aftermarket stereo to stop working properley - Help!

[mofaster]

stopped by the Autozone to have them check what is causing the CEL light to come on my girlfriends 2001 Jetta. After the guy told me what the computer says is causing the CEL, he said he would reset the light in order to turn it off. I thought, cool. Well, afterwards when we drove away, I noticed her aftermarket stereo system was not working properly. Had to turn the volume all the way up, and it just sounded very very muffled. Has been working perfectly up to that point, in fact, was listening to it as we drove into the Autozone parking lot.

Obviously, resetting the code light did something, but I have no clue. I checked the fuses for the stereo, disconnected the battery terminals for a few minutes, but nothing. It's an Alpine 9826 head unit with a JL audio amp.

Could this be something with the security system?

Thanks for any help!!

[boschmann]

It could be the stereo was improperly connected to the car's wiring harness. It's a well know VW problem, dealers won't even connect their computer to a car with an aftermarket stereo. Do a Google search on "VW stereo k wire".

[veedubmechanic]

I've noticed that alpine cd players are more common to cause this than other manufacturers.