errolmenendez

Hello all. i know i'm new here, but not new to Audis VWs or cars in general. I bought the car as a non runner. so unfortunately i have no first hand knowledge of it ever running. I'm grateful to this forum for all of the information i've accrued along the way in diagnosing and eventually finding this problem. unfortunately, i'm upset there may be no inexpensive solution.

Here's the problem. as soon as i connect the negative on the battery, the 5a ECU fuse instantly blows (this is what was causing, or part of, my crank no start problem with the car). i was reading on here about a fella who was asking if these ECUs can be bench tested somehow. He called his ECU a "deadshort" ecu, because like mine, it would instantly blow that 5a fuse as soon as the ecu is connected.

Any help on this matter is appreciated. if there are any further diagnostic tips i should go thru, i'll do so and respond ASAP. thank you again.
-Errol

errolmenendez

for reference The ECU p/n is 4A0 907 551 AA

UrS4boy

The problem is might be a bare coil wire just where they enter under the "20V Turbo" coil cover is shorting out. The switched ECU power is in the yellow fuse holder. If it is the 5Amp fuse, you might have an ECU that was drowned by water and has now corroded and is shorting out internally. If this is the case, you might be able to get Steve Eiche in Armada CO to fix it (for $$), otherwise you'll need a good used ECU.

Check out this link: https://www.audiworld.com/forums/sho...&highlight=ecu

errolmenendez

Thank you urs4boy. My s54 fuse was surprisingly not blown (even tho the coilpack wire on my #1 cyl had broken wires that looked like they were touching) upon further inspection, the coil wires had ALL been repaired at some point with crimp connecters and electrical tape all over. However, the s72 (injector power) thermo fuse was blown. I disconnected the white coil connectors at the firewall, and the 5 amp ecu fuse still blows when ecu is plugged in.
Thank you for you reply! Is that fella steve still repairing ECUs? I read a few older threads that mentioned he wasnt activily repairing them for private customers anymore. For my sake I hope he will help me! Haha

UrS4boy

If the 5 amp fuse in the red holder is blowing then there is definitely an ECU issue. I have PM'd you Steve E's new contact info.

errolmenendez

Brilliant. Message received. Thank you sir!

errolmenendez

Just as an update to my thread, I spoke with Mr. Steve E. and he helped me confirm over the phone that this is an ECU issue. i shipped out the ecu today. i'll keep the thread current with info as it comes in, at least for the sake of future searching. thanks UrS4boy for your help!

moorewr

Makes me wonder if the previous owner went to the same mechanic as my car's previous owner...

errolmenendez

That above photo looked just like my coils as well. i bought the 034 mk5 coilpack conversion harness and called it a day.

just as an update to my thread: My Ecu was indeed "fried". i had it repaired by Mr. Steve Eiche, and he socketed the ecu as well as installed a stage 1+ tune. i had to buy a 3 bar map and reinstall it all, but the car fired up for the first time in my ownership. oohweee that was sweet thanks everyone for their help and advice. now, on to the next issue...

foti40

I am having a similar issue on may car. Red fuse pops instantly. Can someone PM me his contact info?