Weird Electrical problem

[Kaane]

I have a 2000 A6 2.7T I am working on, it has a EPC light, Tach is not working in the cluster and has a Cluster Communication Error to the ECU. Also the stereo has no sound.

EPC Code is P1676 35-00 K132 Circuit
Cluster has a 01314 - Engine Controle Module - 49-00 No Communication

I was under impression EPC code is usually related to Throttle Body. The engine revs fine and throttle seems unaffected. The tach issue points to communication issue between cluster and ECM. Anyone run into something like this?

[HereWeGrow]

In my S4 my EPC light would start flashing and I wasn't able to accelerate. Never did figure out what was causing it because I was t-boned shortly after that happened.


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[Kaane]

Fixed the cluster communication. They replaced the ecu a while back and had adapation set to 1025, since this is earlier bosch maf ecu, it needed 0 instead. Once I changed the adaptation tach started working and the lcd panel starting displaying proper info. Still have EPC light, but I am sure it's TB related, so I will swap it out with my friends to test.

[Kaane]

Now my sound issue. Anyone know if the bose amp has a separate fuse? My Radio is getting power, but I am getting zero sound. CD Changer also seems non operational, won't eject I am guessing power related.

[4rings2turbos]

CD eject is somewhat common failure. No sound could be an amp issue. Once place to check is the amp harness in the back behind the right hand cover in the trunk/cargo area. They can corrode and that's where all the speaker connections are. Not likely if it wasn't crackly before giving out, but at least an easy thing to check. Not sure if these amps die but you could also try to find a known good amp. They're easy to swap.

[Kaane]

Checked the brown plug by the amp, I have 12V on the brown wire, but I don't have power on the Red/Blue with radio and ignition on.