Coolant leak through wiring harness cooked ecm
 

Can anyone who has had this issue please post a reply. I have a 2013 a4 manual that has had all sorts of issues but now have found coolant has traveled up the wiring harness and ruined the ECM. All of the other issues the car had with misfire etc was directly related to this issue.

The other day drove the car for 4 miles to get it to my driveway and the coil pac on #4 melted... yes melted. I think this is a bigger issue and just want to test the waters..

I've got that issue. 2013 A4 manual. It apparently started with the N488 "transmission coolant valve" leaking (they've updated the part to a sealed version since). The coolant traveled to the ECU where it puddled. It corroded some of the fuel injector connections at the ECU, and seems to have traveled through a different wire from the ECU all the way to the connector for the waste gate bypass regulator valve, because that connector had green coolant in it when I disconnected it.

So far it seems like my ECU is OK. I replaced the transmission coolant valve (easy job). I'm going to replace the corroded pins in the ECU connector and replace the wet connector at the waste gate, and hope for the best. The dealer (Ira Peabody) quoted me $5230 to fix the problem. They wanted to replace the entire wiring harness and the ECU I guess. Unclear. I paid them $350 for a diagnosis but got almost no details except "this will cost $5230 to fix". I'm aiming to fix it myself for less than I paid them for the diagnosis :)

I attached a photo of my 60-pin ECU connector showing corrosion at pin 35 (transmission coolant valve) which I think is the source of all the problems.
https://cimg8.ibsrv.net/gimg/www.aud...37d91d0f91.jpg

These TSBs seem relevant:
https://static.nhtsa.gov/odi/tsbs/20...58574-8951.pdf
https://static.nhtsa.gov/odi/tsbs/20...53889-6593.pdf

... coolant migration is the term they have adopted for this age-old problem.

Leave it to Audi to have a name for a problem that shouldn't exist. ever.

https://cimg6.ibsrv.net/gimg/www.aud...b724804f94.jpg
https://cimg7.ibsrv.net/gimg/www.aud...9f6f4b8665.jpg

So the worst case scenario at the dealer was 3k for a full harness and the ECU. If you have the time and the knowledge it appears an easy job. My issue was that it affected the 4th cylinder and then i had a spun cam lobe, so cam and lobe were in need of replacement. My car started on fire.. as you can see mine was a little worse. Dealership did mine and only replaced the "affected wires " and seems to be working now. thanks for the reply.

Is this limited to certain models, and where is this valve located?

sorry didn't get notification of the reply.. I bought my audi from HERB CHAMBERs. Burlington. DO NOT EVER trust these guys .. a total harness and ECU is 3k. These a-hats, fixed my car and then told me something else was broken and i had another 3k to have to fix it. I had them send the car back to me. The part they said was broke was 30 bucks. the local dealer did me a favor looked the car over and nothing was wrong with it. my other point after my rant for that crappy dealership is that the ECM and total harness if a dealer did it would be 3k.