Was driving to work a few minutes ago and car shut off. Check engine light does not illuminate either. I checked the engine control fuses and those check out. Also changed the ecu on the side of the road and nothing..
04 Jetta gli 1.8t
Ecu isn’t turning on so I can’t check codes....
Any ideas?

Well shit. Didn’t think of that on the road in this freezing temp.
Got a ride to work guess I have to wait now and see and try my spare relays I have from the other parts cars
Thanks for the input man

To get off the side of the road I jumped the relay from the sai hot wire and the car runs
Changed the relay under the dash and still nothing. I get continuity on the ground signal wire for the relay to the ecu

There is no voltage on the two 12v wires for the main relay unless obviously if I jump it to a battery hot

I’m out of ideas

i bought a new relay from vw and changing that by itself didn't do anything.
checked the fuses with a volt meter in continuity mode  blah blah nothing.
took every fuse from a know working parts car and swapped them over and now the car turns on fine etc.
BUT
odd thing is that i think the EPC light is supposed to stay illuminated when key is on. when i turn the key to the on position, it blinks quick then turns off(blinks as in turn on for a split second then shuts off)
can someone verify this for me?

Ecu gets power.. car runs and no errors.
I’m just concerned as to why the epc light just flashes quick instead of staying on when key on

So, what did you change?