AEB 1999 1.8T - Would the ICM or ECU stop one coil working?

[anorak_ian]

No pulse (signal) reaching coil no'2, the cable seems to be ok with no brakes or shorts.

Is it possible that the Ignition Control Module could cause one coil to stop pulsing?
How do I Check that the ICM is working ok?

Same question with the ECU?


Getting very close to scrapping the car now.

[Peter D]

Connect an LED and a 220 ohm resister in series and connect it to each coil in turn at N122 and the other end to a 12 volt feed and you should see a short flash each time it fires. Regards Peter

[anorak_ian]

Thanks for the reply Peter.
Where is N122? The wiring diagram says it's the Final output stage. Would that be the ICM?

Sorry to be a pain.

[Peter D]

Just follow the cable back from the coil packs and there it is. Regards Peter

[anorak_ian]

Yes it is the ICM on top of the air filter box.
There was / is no way of getting back to it via tracing the cables back from the coils, as the cables join a load of others in the loom and get lost up it's own behind like a wooselum bird (sticks it's head up it's self until it disappears, Carry on films, lol).

I have found another post on another Audi forum, a guy had the same problem on his car. Others remarked that this is old news and is a common problem. Turns out that the original post was over ten years old now!

So that seems to be that. If you have a 1.8T engined car A6 A4 TT Pasat ect ect ect with no signal to one coil (usually no'2 as in my case) then it seems it will be the ICM.

A lot of good vag com was, lets see if those water temp and MAF sensor errors disappear with a new ICM.

[anorak_ian]

New ICM on and all working well the maf problem the VAG com reported has gone, but still shows a problem with the water temp sensor.
Thanks for your help.