BMW E39 540 electronics

BMW E39 540 electronics

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Discussion

UncleM

Original Poster:

41 posts

234 months

Wednesday 12th July 2006
quotequote all
Hi,
The electronics on my 98 540 is playing up intermittently. Frequently when turning the ignition on, the music console, phones, wippers and horn don't work. They come back on after some varying time after the car's been running for maybe 5 to 15 minutes. Anybody else seen this? Is this something I can fix myself. Thanks.

off_again

12,812 posts

240 months

Wednesday 12th July 2006
quotequote all
The one that I keep hearing about is the dash going freaky, speedo not working and the rev counter going wild. Funny thing is though - the gear selector indicator works fine. Turns out that the CD changer can go potty and it freaks the whole bus electronics out - in this case its the dash....

So I would check what you have and try disconnecting a few things - like CD changer, phone if you have it and even the stereo too. Eliminate what the options are and see if things return to normal. Also try disconnecting the battery (its not as hard or dramatic as you might think) as this will reset everything (well most things) to their standards again. It should work, but since everything is connected to the bus then it could be anything.

Oh, and check all of your lights (have you upgraded the lights?). Any dead bulbs or dodgy connections should be checked and fixed. Again, the light module for the headlights (with aftermarket xenons or angel eyes) have been known to confuse the hell out of the system too....

Usually the electronics are very solid, its just that you get really weird problems when something does go screwy....

_Deano

7,408 posts

259 months

Wednesday 12th July 2006
quotequote all
how about running a diagnostic through the OBC. I've been told that the readout are very specific on the e39's and finding the problem should be quite straight forward.

UncleM

Original Poster:

41 posts

234 months

Wednesday 12th July 2006
quotequote all
Thanks for the suggestions, I'll give them a go this weekend.

UncleM

Original Poster:

41 posts

234 months

Friday 21st July 2006
quotequote all
Disconnected the battery and centre console seems to be behaving fine so far, thanks.

UncleM

Original Poster:

41 posts

234 months

Wednesday 16th August 2006
quotequote all
Problem came back and had to have it resolved at the dealer.
It was due to a faulty ignition switch. So if you have similar problem source yourself an ignition switch and save yourself the dealer costs.