1998 Audi A8 D2 (4D) 2.8 30v No response from engine ECU

Inexperienced Joined: Jun 26, 2004 Posts: 42

My car started cutting out whilst driving. For the first few times it will start straight up again but after a few starts it will just refuse to start for a day or so.

When it wont start there is no spark and no fuel pump and no response to diagnostic scan. The engine does turn over on the starter motor though.

When I bought the car I got the diagnostic codes from it and there was just engine stopped by immobilizer but I thought this was just an historic code.

-------------------------------------------------------------------------------
Address 01: Engine Labels: None
Part No: 4D0 907 551 M
Component: 2.8L V6/5V MOTR AT D02
Coding: 04153
Shop #: WSC 02324

1 Fault Found:
17978 - Engine Start Blocked by Immobilizer
P1570 - 35-10 - - - Intermittent
Readiness: N/A

-------------------------------------------------------------------------------
My understanding of the immobiliser lockout is that the engien will always start but cut out within 1 or 2 seconds. So this sin't my startign problem

I read on Ross Tech Wki that some cars have an engine ECU relay. This would explain why I can't scan the ECU when I have the problem.

Is there an engine ECU relay on my car?

Or should I look at the immobilise wirign as I also had:
-------------------------------------------------------------------------------
Address 25: Immobilizer Labels: None
Part No: 4B0 953 234
Component: IMMO AUZ9Z0W6025425 D03
Coding: 00000
Shop #: WSC 00089

1 Fault Found:
01176 - Key
07-10 - Signal too Low - Intermittent

-------------------------------------------------------------------------------
I have tried the other key also.

Inexperienced Joined: Jun 26, 2004 Posts: 42

Another question.

Are there any cables running in the right hand side sill?

I ask because I had a flat tyre the other day and I jacked the car up with the jack in the wrong place (it was too low to see in my work clothes!)

Anyway, I got the flat off and was just about to put the spare on when the car fell off the jack. I wasn't under anything at the time but it has damaged the sill just behind the front wing.

Do any wires run through here? Like the ones going back to the battery?

Site Moderator Joined: Jan 31, 2003 Posts: 9144

there will be wiring running along there. you'd need to remove the seats and lift the carpet to access.

have you checked your drains ?

common problem on the D2 is the drains get blocked. If you lift the carpets on the passenger footwell check to see if it's wet under there. There's a load of relays located behind the board in that footwell. if they get wet, they can cause the cutting out problem

check out http://www.audipages.com for a guide on clearing the drains

Inexperienced Joined: Jun 26, 2004 Posts: 42

Thanks for reply. I will check those drains.

My slightly crushed sill is the area between the jacking point and the drivers door (RHD).

I am sure cables will be running in the cabin footwell areas but I wouldn't have thought in a vulnerable area like I have damaged?

Posted: Fri Dec 16, 2011 4:06 pm

Sounds like a bad CKP (Crankshaft Position Sensor)...it triggers fuel pump relay, injector solenoids and ignition (spark).

Newbie Joined: Jan 24, 2012 Posts: 3

Hiya, had this same problem, bad running, engine stopping etc. called out an auto electrician and he could not read the Engine ECU, he took off the top compartment cover and there was lots of condensation in the unit, he said that the car wasn't starting as there was a 3 second delay from the immobiliser to the ECU of course if the ECU is dead then the immobiliser doesn't understand what to do. sent off the ECU off to:
http://www.ecu-repairs.com/engine-ecus/?kw=ECU%20testing&fl=510190&ci=5391322117&network=s
I was a little dubious to start with but 10 days later it was returned with a repaired chip that had corroded and blown, it cost just over £200, cheaper than Audi stealers, got it back clipped it in place and off she went like a dream, you do not need it to be reprogrammed because its your same ECU and the immobiliser recognises it, anyway after that I sealed round the compartment (Oh I did put in some sillicon ball thingys in the bags around the ECU just to be sure. touch wood not probs since. Good luck.

Newbie Joined: Jan 24, 2012 Posts: 3

Oh by the way, we checked all the usuals, relays, fuel pump etc and all were fine. The car just stopped one day and wouldnt start as the immobiliser kept kicking in.

Newbie Joined: Jan 24, 2012 Posts: 3

Had this problem a week after buying the car too, luckily caught it in time, just need to go under the wheel arch and find the tiny hole, i will say that we took out the rubber washers they seemed to clog up more with them in, since then I just check every now and then for stray leaves etc, no soggy footwell since

Newbie Joined: Oct 22, 2012 Posts: 3

Check for Solenoid starter. It is a small device installed outside the engine. When this device fails, similar problem occurs.

Increase Engine Horsepower

Posted: Wed Oct 24, 2012 12:49 pm

" Solenoid starter" ? ...no such animal. Even if you meant "starter solenoid", you could NOT be farther from correct. Without the solenoid working (which is attached to the starter) the engine would not crank. Every poster here stated that cranking was the ONLY problem they did NOT experience.