GuntherS4

So here is the long and short of it. 2001 s4 manual dies after running for a few minutes, there is no sign of anything wrong when it's on it just shuts off while driving no engine light or anything. I checked for codes and there was nothing. I did some research and all signs pointed to the engine speed sensor which I replaced earlier today and I am still having the same problem. The car will start run for a few minutes and then die again and I have to wait a like 10 minutes for it to actually start again. I went to check the ecu again and now I get no connection to the ecu.( I found out that when the car is cool and has sat for a while I can get readings it only doesn't work if I have had it on for a few minutes). I had an apr 5.0 chip soldered in about 4 years ago so I looked in to check on the solder job and everything seems fine. I am thinking all signs are pointing to my ecu since I also can't switch between stock and higher octane modes. Anyone have any ideas or been through this before?

joeffrS4

Sounds like you diagnosed the problem. If you can't com with ECU it is not available for engine management.

AdamD

Sounds like ECU. I was having problems starting recently and no codes. Did a lot of searching and ECU seemed to be the common gremlin in the results I found. I don't drive enough to know for sure what my issue really is but I haven't had it for a month now.

One thing to look at a little more though is not the soldering but the wiring harness. The wires stripping and shorting may make more sense if everything looks good and it dies while moving

bobbyd1961

maybe its the throttle body. my car died during a hard acceleration, not even a limp mode id have to shut down restart for it to be drivable. they changed throttle bottle but found "debris (piece of plastic)" in line to throttle body. Nice QAQC audi. and the car was brand new. now the car is perfect.