2008 E90 325i Strange Electrical Fault

[mbwoy84]

I've got a 2008 E90 325i here with the 3.0 N53 Engine and it's developed a weird electrical fault. First of all, with the car driving along normally, suddenly every warning light came on the dash and the car cut out completely, very suddenly. The car was unresponsive then, and the key wouldn't lock into place in the key slot.

Then the car was recovered and 5 hours later the car started again, but with the airbag warning light displayed. Then it seemed to clear itself of all faults and warning lights and drive ok again for a couple of days. Then when parked up one time, it wouldn't start again. It would lock the key in, but no start and the airbag warning light on again.

It was left about a week, then on the day it was being recovered, it started again. The fan was constantly on from start up, and it threw up a fault code for a faulty coolant temp sensor, which wasn't faulty, checked what it was reading and it was fine, so cleared that and the fan went off.

Fitted and registered a new AGM battery as thought that might be causing it to play up, with no obvious signs of anything else. Took it for a decent test drive, with no issues. Parked up, checked the whole vehicle for fault codes and there was nothing, so went to start it again and once again it wouldn't start. Key was locked in, airbag warning light, traction control light and service light all lit up, also windscreen wipers came on and won't go off or allow any adjustment until the key is removed.

Read fault codes and it comes up with:

D517 Driving Speed Receiver EPS Transmitter DSC
D515 Steering Wheel Angle Receiver EPS Tranmsitter DSC
A3B3 Instrument Cluster - No Message From Multiple Restraint Systems

To me, they look more like codes that would be thrown up due to an electrical issue caused by something else rather that the cause of this type of fault.

Any ideas? Only other thing to report was it had only recently had the BMW recall completed for the B+ Cable, but as far as I can gather, that's just the positive cable from the battery to the fusebox.

[d_a_n1979]

I know you've said you've fitted a new battery and registered it to the ncar, but have you tried to give the battery/car a good 24-48 hours trickle charge too?

This sounds like battery funny business to me; but also having had similar experiences in an E65, it was simply that the battery had been sat a while and needed a damned good charging to get it to full health

2 days on trickle etc and then a good run and the issues never came back...

Just a thought

[njw1]

mbwoy84 said:

Any ideas? Only other thing to report was it had only recently had the BMW recall completed for the B+ Cable, but as far as I can gather, that's just the positive cable from the battery to the fusebox.

As I was reading through your post I was thinking that you've either got loose battery connections or a bad earth. If the issues have only started since the above recall was carried out I'd say that's too much of a coincidence and would be taking the car back to the garage that did the work.

[mbwoy84]

Got it going again by waggling the fusebox behind the dash. That caused lights to flicker and other things to happen, then the car to fire up. It felt like all the fuses were kind of loose, so gave all those a push and it's ok no, apart from it throws up a steering lock light (pretty sure car isn't equipped with steering lock!), accompanied by a general CAS fault code.

Looks like the recall is for a cable that connects to that fusebox, so guess that's the problem...

[mbwoy84]

Just as an update, it seems the problem was the faceplate on the fusebox hadn't been located securely, which must have happened on reassembly from the recall. It was fine for a while before the problems started, then seemed like the faceplate was slowly moving outwards, probably from the vibrations etc from driving, which started pulling the fuses out. I gave the faceplate a good knock in and it seems to have located properly, and then pushed all the fuses back in properly, and *touch wood* all appears to be ok. But if it plays up again then it can go back to BMW, but as far as I can see with the dash in place, it seems to be properly located now.