Horn, window switches, turn signals, cruise control, wipers not working...

[marriux1]

Hey all. The other week I got in my car and since I live in Florida and it's starting to get nasty hot outside I went to lower my windows. Too bad none of them would go down if I pressed on the switches. After I lost my mind for a little bit I said whatever and got in my car. When the time came to use my turn signals, they weren't turning on. I quickly realized that most of my electronics aren't working.
Car is a 2002 Audi A4 Quattro 1.8T.

Not working:

• Horn
• Windshield wipers
• Cruise control
• Window switches to lower/raise windows
• Turn signals
• High beams
• Knob to adjust side mirrors

Working:

• Car stereo works just fine.
• Hazard lights work.
• Low beams work.
• Break lights work.
• AC works.

I looked around the web and I was lead to believe that maybe it was my ignition switch that died. Being a cheap replacement, I bought one and switched it out today. Nothing changed and my electronics are still dead.
I am now wondering if my CECM might be at fault. What do you guys think? I just want my baby to be functioning again

[diagnosticator]

The CECM may have been damaged from water overflowing from the plenum under the windshield. The CECM is located under the driver's side dash, below a horizontal row of relays, and it is mounted upside down so water can get inside if the plenum overflows. If that happened, lift the drivers side carpet and check for water under the carpet. The comfort module is located in a box forward of the driver's seat under the carpet and could be flooded too.

Most of the inoperative devices listed are controlled by the CECM except the power windows that are controlled by the comfort control module under the driver's side carpet.

Scan the CECM and comfort modules for DTCs stored, using VCDS.

[marriux1]

The CECM may have been damaged from water overflowing from the plenum under the windshield. The CECM is located under the driver's side dash, below a horizontal row of relays, and it is mounted upside down so water can get inside if the plenum overflows. If that happened, lift the drivers side carpet and check for water under the carpet. The comfort module is located in a box forward of the driver's seat under the carpet and could be flooded too.

Most of the inoperative devices listed are controlled by the CECM except the power windows that are controlled by the comfort control module under the driver's side carpet.

Scan the CECM and comfort modules for DTCs stored, using VCDS.

Yup seems that the CECM got some water on it after it rained last week. Mine is part number 8E0 907 279 E. If I get one with the same part number will I still need to code it using VCDS?

[diagnosticator]

Yup seems that the CECM got some water on it after it rained last week. Mine is part number 8E0 907 279 E. If I get one with the same part number will I still need to code it using VCDS?

If you buy a used CECM from the same model year and equipment list, probably no. But you won't know for sure what the coding stored in the used module is without at least opening the module in VCDS to view the coding value stored.

The drains in the plenum need to be cleaned out too. To access the plenum drain, the battery must be removed. There is a rubber "duck bill" one way drain valve fitted, I recommend removing that check valve since it is a trap for small rubbish to plug the drain.

You also need to check under the carpet for water, and check the box with the comfort module inside for flooding.

It may be possible to restore both control modules to normal operation, by opening the module housing and removing the circuit board. Rinse the circuit board in isopropyl alcohol, and dry with a hair drier set on warm setting. When the circuit board is fully warmed up set the board aside for 24 hours then reinstall and test for function. IF the board still does not work, then it will need to be replaced for sure. Handle the circuit boards by the edges only.

[old guy]

In addition to the plenum drain underneath the battery there is also one underneath the brake booster. If that one gets stopped up it will most definitely dump water on the CECM. With a set of ramps you can access it easily from underneath the car. You don't even need to take off the belly pan. You can reach up and clean it out with your finger. Be prepared for a face full of water.



Here's the drain that sits underneath the battery. You can also reach this from underneath the car. It's a little harder to get your arm up there but totally doable. I check both of mine every time I get underneath the car for any reason. If you find a lot of debris it's worth removing the battery to get it all out.

[marriux1]

If you buy a used CECM from the same model year and equipment list, probably no. But you won't know for sure what the coding stored in the used module is without at least opening the module in VCDS to view the coding value stored.

The drains in the plenum need to be cleaned out too. To access the plenum drain, the battery must be removed. There is a rubber "duck bill" one way drain valve fitted, I recommend removing that check valve since it is a trap for small rubbish to plug the drain.

You also need to check under the carpet for water, and check the box with the comfort module inside for flooding.

It may be possible to restore both control modules to normal operation, by opening the module housing and removing the circuit board. Rinse the circuit board in isopropyl alcohol, and dry with a hair drier set on warm setting. When the circuit board is fully warmed up set the board aside for 24 hours then reinstall and test for function. IF the board still does not work, then it will need to be replaced for sure. Handle the circuit boards by the edges only.

In addition to the plenum drain underneath the battery there is also one underneath the brake booster. If that one gets stopped up it will most definitely dump water on the CECM. With a set of ramps you can access it easily from underneath the car. You don't even need to take off the belly pan. You can reach up and clean it out with your finger. Be prepared for a face full of water.


Here's the drain that sits underneath the battery. You can also reach this from underneath the car. It's a little harder to get your arm up there but totally doable. I check both of mine every time I get underneath the car for any reason. If you find a lot of debris it's worth removing the battery to get it all out.

Thank you both so much! I'll let you guys know what I end up doing.

[marriux1]

So my problem ended up being fixed by the dealer. WAS NOT CHEAP. They replaced the immobilizer and my key, as well as the steering wheel control module.