Leon 20vt ecu no power

[Chrish882]

Hi everyone this is my first post, have just recently bought a mk1 2003 cupra 20vt had the Octavia vrs 2008-2012 then sold because of company car wanted a car with that engine again and always liked the Leon so when this came up I bought it as a weekend car. So the problem is it say on the drive for 2 weeks not started came to start on Saturday would turn Over but not start hooked up vag com and could not communicate with Ecu would communicate with every other system bar engine ecu, did a control module finder and the ecu came back online, was fine for the rest of the day no faults in ecu. Went out to the car on Sunday same problem this time vag com did not find it, I have no cel light and no epc light on dash when these are lit the car starts when they are not it doesn't. The fuel pump is priming when you open drivers door. I have checked the fuses all look good I have checked relay under bonnet next to Maf is clicking when ignition is on the, relay 100 under dash clicks when ignition is turned on, relay 423 clicks when fuel pump is priming then unclicks. I've searched the net and this seems to be a common problem but no one has posted the answer so I'm here asking for advice. Thanks.

 

[Chrish882]

Update just incase anyone has this issue in future.
Was a wire next the ecu plug where wire from relay 423 reduces and is split one end towards fuse box and the other to Ecu PIN number 4. The wires are bent by around 90 degrees to plug into Ecu and this wire has snapped causing no power to ecu and no communication to Ecu through vag com. Joined up and problem is fixed. Hope this can help people in future.

 

[ibizacupra]

thx for sharing the fix
good work

 

[nd-photo.nl]

Indeed, gave some rep points for sharing it.

 

[Mozboosted]

I had this problem before and have again it can also be due to water leaking in from the windscreen drain, my ecu harness wires have been wet before. Gonna try this wire fix before buying my 3rd ecu in 12 months.