E39 M5 Not starting

[Valdelisbmw]

thats explain a lot. it was working till U disconnect the battery ,very common fail . now must to found there wires are going to from this switch .or how to reset it ,if its possible

[Murdoch]

I'm 90% sure this problem started after I disconnected the battery but not 100%. I phoned a company who can reprogram it and give new fob keys but there are a lot of wrires going into it and it seems that I can't plug them out. I'm going to wait for my obd scanner before I start because otherwise I have to strip the car apart to remove this box ...

One Other thing is, it's strange how it happens just now, this was installed in 1999 :-S

[Foxhole Norman]

I had a very very very similar issue to this on my 525i. Recheck the fuses in the glovebox, I think it was Engine Control, 14/15 that had the tiniest of tiny breaks, an auto electrician missed it! I spotted it and that solved my issue immediately. I had same symptoms, all lights would work with ignition but not even a click, replaced the fuse and boom, started right up like there was never an issue.

[Murdoch]

Hey!

Actually I'm having an issue where none of the lights come on except the airbag, which then goes out! But I will double check all the fuses again tomorrow!

[Foxhole Norman]

Ah right, I read your opening post as the standard set of lights come on with the ignition, my bad!

[Murdoch]

Ok so I went to read codes today but neither the 16 pin nor the 20 pin were connecting with my laptop (I've used this laptop on my 525d before so I don't think it's that) l. Of course only position 1 of the ignition is doing anything so maybe that has part to do with it. Next step is to get an auto electrician to remove the alarm / immobiliser as it looks too complicated for me

[Smokey Bear]

That sounds really odd, it means there’s no power coming back to your diagnostic plug.

Really doesn’t sound like the alarm at this point.

[Murdoch]

Does the obd in this case require that the dashboard all lights up I wonder - regarding the key / ignition? I was just thinking that it was caused by that but maybe not?
adding also that I checked fuse 15 when i plugged it in and it didn't work

going to test the pinouts of each wire in the ignition switch in all 4 positions tomorrow

[Murdoch]

Small update - tested the pins at the ignition switch. Not every pin on my connector had a cable going into it - only 7 in total. Anyway everything had 12v, including the starter when I turned the key fully forwards (absolutely no noise when I do this).

[schoonerm3]

Wish I could be of assistance. But I know nothing about this. Best of luck