HELP !! 2.2 20v S6 electrical issue

[fishbone13]

hi i have just bought a non runner c4 s6 avant 1996. (AAN i believe)
i'm aware this isnt an s2 but have been assured i wont find a better site for brains on these engines/electrics.

right as i said the car is a non starter, had been sat for 2 years on a farm and i was able to buy it for a tidy sum, now the car does not start, the guy i bought it from has tried to jump start but to no joy.
i bought a brand new battery and starting checking to find firstly no fuel and then no spark, i have been through the fuses and various relays and found what is described as a thermal fuse for the ecu has blown. looking at my diagram the fuse is on the main feed for the engine ecu (pin 18). i replaced the fuse which immediately blew again ., so i guess what i'm asking is has anyone come across this or any thing similar or can anyone make a suggestion as to what i may have missed etc.
i contacted a couple of ecu repair specialists that we use at work but none of them seem to be able to check or repair this number ecu.

any help would be greatly recieved and any info a bonus.
i am also keen to know if there are any more comprehensive diagrams and or a list of relay locations and purposes. and if anyone knows which ecu pin is the main earth.

thanks in advance

[Pirvu Eugen]

Remove the maf plug and replace the fuse...is a 5 amps one. iff the fuse blow out again..then is the wiring or the ECU....could be also the fuel pump relay..

[Pirvu Eugen]

look here!
Maibe helps!

[HMS-S6]

hi i have just bought a non runner c4 s6 avant 1996. (AAN i believe)
i'm aware this isnt an s2 but have been assured i wont find a better site for brains on these engines/electrics.

right as i said the car is a non starter, had been sat for 2 years on a farm and i was able to buy it for a tidy sum, now the car does not start, the guy i bought it from has tried to jump start but to no joy.
i bought a brand new battery and starting checking to find firstly no fuel and then no spark, i have been through the fuses and various relays and found what is described as a thermal fuse for the ecu has blown. looking at my diagram the fuse is on the main feed for the engine ecu (pin 18). i replaced the fuse which immediately blew again ., so i guess what i'm asking is has anyone come across this or any thing similar or can anyone make a suggestion as to what i may have missed etc.
i contacted a couple of ecu repair specialists that we use at work but none of them seem to be able to check or repair this number ecu.

any help would be greatly recieved and any info a bonus.
i am also keen to know if there are any more comprehensive diagrams and or a list of relay locations and purposes. and if anyone knows which ecu pin is the main earth.

thanks in advance

Did you but this car from a farm in Devon by any chance? Auto gearbox?

[fishbone13]

hi no its a manual, i did get it from a fram but in berkshire

[fishbone13]

Did you but this car from a farm in Devon by any chance? Auto gearbox?

i have tried that as i saw on the diagram that it is linked through the ecu and it still blew, yes its the 5 amp one.
will try again to double check, i did check the resistance between the ecu plug and the maf and it seemed good.

[fishbone13]

look here!
Maibe helps!

this is the same digram i have, i was hoping to find out which relay does what, and if i can get a ecu from another car or is it key coded ?

[Pirvu Eugen]

Yours is RHD...at the LHD i knew some....dont know iff they are the same. Not all the ECU's have immobiliser. I'd check further before swaping the ECU..they dont go bad so often.
I will look in autodata to see iff i have something.

[fishbone13]

Yours is RHD...at the LHD i knew some....dont know iff they are the same. Not all the ECU's have immobiliser. I'd check further before swaping the ECU..they dont go bad so often.
I will look in autodata to see iff i have something.

thanks for your help so far, i am sure the key coding is separate as the orange imobilser symbol on the dash comes on and goes off as it says it should in the owners handbook and also i can read the immobiliser codes using my vag-com

[HMS-S6]

thanks for your help so far, i am sure the key coding is separate as the orange imobilser symbol on the dash comes on and goes off as it says it should in the owners handbook and also i can read the immobiliser codes using my vag-com

If its been sitting, have you checked that the ECU plug has not had water travel down (capiliary effect) the wiring into it? Very common on the Jags that i'm used to working on!

Did it run before sitting or is that why?

[fishbone13]

If its been sitting, have you checked that the ECU plug has not had water travel down (capiliary effect) the wiring into it? Very common on the Jags that i'm used to working on!

Did it run before sitting or is that why?

bone dry in there, the guy said it did run and then he stopped using it, but i am taking that with a pinch of salt as he may just have been trying to sell it

[S2central.net]

If you want me to check ECU over I can do so on 'no fix no fee' basis - blowing that fuse its probably because of a protection component inside that has failed - pretty common IME - but not always the case. Components are pennies but finding the faulty one is what takes me time - and if I cannot repair, then no cost incurred - other than postage back to you.

Don't go messing with IMMOs and stuff in case you screw up the coding - should be an easy ECU fix.

[fishbone13]

If you want me to check ECU over I can do so on 'no fix no fee' basis - blowing that fuse its probably because of a protection component inside that has failed - pretty common IME - but not always the case. Components are pennies but finding the faulty one is what takes me time - and if I cannot repair, then no cost incurred - other than postage back to you.

Don't go messing with IMMOs and stuff in case you screw up the coding - should be an easy ECU fix.

awesome , pm me your details and i will get it sent to you, that would be a great help.
i am going to have a mess about tomorrow night for a few hours and try to determine if it is the ecu or not. i will be in touch.

what a great forum

[S2central.net]

Can you wait a week or so as I have a big hassle with another broken car that needs to be repaired asap.

Meantime - try and borrow a nonimmo ecu from someone else to ascertain that the engine sensors are good and that the car can actually start with a healthy ecu.

[fishbone13]

Can you wait a week or so as I have a big hassle with another broken car that needs to be repaired asap.

Meantime - try and borrow a nonimmo ecu from someone else to ascertain that the engine sensors are good and that the car can actually start with a healthy ecu.

can i use just another ecu? is the immobilser system not run through the engine ecu?
i am pretty sure that it is definately the ecu, tonight i disconnected all components and various relays and still popping the fuse, so not sure if its the best approach but i earthed pins 10, 14, 19 & 24 directly into the ecu which appear to be the main ecu earths (with the ecu unplugged) and put a fused feed into pin 18 (main feed)to simulate away from the car loom and i still get the same fault with the 5 amp fuse blowing.

i am up for sending mine to see if it can be fixed but am willing to look on here for another ecu to try for now as long as its inter changable ie no immobilser issues wiith coding etc,
i'm sure i saw one for sale on here from an aan

thanks again people