# Fault code 00638



## edds30 (Jul 23, 2013)

Hello!I have fault code on my audi a6 c5 1997 1.9AFN automatic. The code is "00638 - Engine/Transmission Electrical Connection 2 03-10 - No Signal - Intermittent" The wires are ok. I don't know with what to start. Maybe someone can help me. I can feel that sometimes car drives not so good. The kick down doesn't want to work.


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## MikkiJayne (Jan 1, 2007)

*FV-QR*

A common problem with the C5 is water ingress in to the passenger side footwell through the heater. This happens because leaves and dirt block up the rain tray drains, then it fills up with water and the first place it goes is through the heater motor. Just for giggles Audi put the TCU and the convenience unit underneath the carpet on the passenger side, so when the water gets in it corrodes the connectors and eventually drowns the ECUs.

First thing to check is the rain tray around the battery and see if its full of water and / or check the carpet on the passenger side. If its damp then its likely the corrosion is whats causing the problems...


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## edds30 (Jul 23, 2013)

Once, I already looked what happens in the passenger side and there was wet little bit but I didn't see corrosion on the ECU or somewhere else. But it means that I need to clean the drains. I didn't look what happens around the battery. Thank you for your ideas.


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