Now, the jump wasnt by me.

Ign on- no comms, no fuel pump prime.

With terminals 30-87 bridged on engine management relay plate the pump primes, the injectors etc power up and I get coms

No fault codes but some of the live data doesnt seem to be right (EG the temperatures seem rasonable but I get no responce from TPS output)

But it still wont fire or inject.

Car was fine before battery ran down

Interestingly the radio no longer works. I suspect that it has been reverse poled during the earlier attemp at starting it though I cannot confirm this.

a) Is there any (easy) way of checking for this? (and would it explain symptoms)

b) Should I be checking something else. I am charging battery off vehicle at present and will likly see it again after the weekend.

Paul,
How did you get on with this one ?
I would imagine you have or had a blown fuse?

I am almost certain that this has been reverse poled (The customer admits that her boyfreind was startled by a big spark when he initially made the battry connection)

I have not been able to find any blown fuses, and the relays all seem to work.

I am unable to check the wiring further because, although the Siemens ECU part number is correctly listed in Autodata, the pin out diagram does not correspond with reality!

(Note to autodata, absent information is irritating, incorrect information can cause serious damage! At least in this case it is "Obvious" that the data is incorrect. It is however not always the case!)

I would like to send the unit off for checking but BBA claim not to work on these units.

It is a Siemens MS41.0 I "think" the BMW number is 1 429 861 (there are loads of other numbers on the unit but it is not clear which one is actually the part number)

Any suggestions

(These people http://tunemycar.com/ claim to be able to deal with this, but the girl on the phone didnt seem really sure and I have not used them before. Any body used them before??)

If you get coms when you power it up manually then its unlikely to be an engine ecu fault.

What year is v plate? I think its an e46, right? VIN would help to ID it.
Can you com with the cluster, either when powered manually or not?

The E46 cluster is the gateway. Establish first if the cluster has coms then chase it from there. Ignition switch could be at fault too.

I think I have given up on this one (for various reasons including the fact that open ended problems like this are not really a field where mobiles can operate well)

Is there anybody in the Aldershot area with Autologic (or equivilant) who could take this on otherwise it is off to Mr BMW with it

Paul

Hi it might be worth looking at the ignition switch I have changed them on a few cars.

HTH

The worrying thing with this is the wrong data that AD shows, 700 quid a year for subscription and data wrong, Matt from AD used to post here and is a sponsor of the site,does not post now, I wonder why ????

Just heard today.

It was, as I suspected, the ECU!

Replaced by BMW

£900 quid!