2.7t wont start after timing service

B5 S4/ RS4
#1

I have performed this service on two other cars without issue. Here is the short of it, I had installed a gates racing belt and could not stand the whine from it any longer, plus I had a boost leak with a torn throttle body boot. I ordered new 710’s valve cover gaskets and an aluminum thermostat housing. I replaced them all, in the mean time my battery died and I tried jumping the car off without any success. Installed a new battery and all seems fine other than no spark from either bank. 40 amp ECM fuse was blown and replaced still no spark. VCDS cannot communicate with ECM. Trans gives me p1850 missing message from ECU.

Any ideas? I hate having it towed to the yahoo’s around here…

#2

Can you connect to any of the other modules.

#3

Yes, so far it is only the ECM I cannot communicate with.

#4

I assume the starter still spins. Depending on what happened you might have taken out the ECU. Obviously check all the fuses that work or support the communication lines but I know its possible to short out the ECU

#5

I will double check them tonight. Yes the starter spins, it seems to be supplying fuel, but no spark. Are there any fuses beyond those in the main panel and the single 40 amp in the ecu housing?

#6

Did you check fuses 29, 32 and 34?

#7

Are both your amps blown…

#8

I checked all the fuses and all seem fine. I only see one amp fuse a 40 amp next to the ecu. Is there a second one some where?

#9

Is there a way to test the unit outside of the vehicle? Can a dealer do such a thing?

#10

you have to amps that plug on and connect to the air box. If you don’t have those plugged in you won’t get any spark

#11

Both were connected. I bought another ECU and it fires up but shuts down due to the immobilizer. I will need to work on reprogramming things.

My old ECU had an APR tune on it. I would like to salvage the unit if possible. Is there a means to test it? Should I bother taking it to Audi?

#12

Anyone? Sorry to be a bother.

#13

You can contact JHM and send them both ECUs ask them to clone your one ecu onto the other. Doing so will transfer your immob and the calibration.