Garage Support

Back to Forum

Post a Response

BMW Mini 2004 - SRS light on, code OB #

Posted by Peter Rainsley on July 29, 2011, 9:13 am

Year of Manufacture *: 2004

Can anyone help with a better description/explanation of the code read on this Bosch MRS 4 system. Autocom gives OB, battery positive terminal isolation 1, resistance too high, and ACR4 gives 11, battery positive terminal resistance. I have cleaned and checked battery connections, but need guidance to go further. Any help greatly appreciated,
Peter

Re: Mini SRS light on, code OB

Posted by Kevin Apps <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT2589' width='330' height='300' border=0 style='border:none;'> on July 29, 2011, 10:03 am, in reply to "Mini SRS light on, code OB"
Kevin Apps

Peter.

My laptop with my mini info has crashed, but looking at other info.

No OB code but B battery positive terminal isolation 1 (there is info on this on BMW,s in the archives)

Code 11 belt tensioner rear left.

HTH

Kev.

Re: Mini SRS light on, code OB

Posted by ian slattery <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT1196' width='330' height='300' border=0 style='border:none;'> on July 29, 2011, 2:10 pm, in reply to "Re: Mini SRS light on, code OB"
Ian Slattery

I haven"t any info on the code, but on certain minis the wiring loom catches on the steering column. Maybe worth a look.

Re: BMW Mini 2004 - SRS light on, code OB #

Posted by Alan Kane <iframe src='https://members4.boardhost.com/ukautotalk/info/user=alankane' width='330' height='300' border=0 style='border:none;'> on July 29, 2011, 3:00 pm, in reply to "BMW Mini 2004 - SRS light on, code OB #"
Alan Kane - Administrator

0B is hex for dec 11, ie same thing, so both tools are showing you the same code.

The fault code is telling you the resistance of the circuit for the battery isolator is high.

Re: BMW Mini 2004 - SRS light on, code OB #

Posted by Peter Rainsley <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT5418' width='330' height='300' border=0 style='border:none;'> on August 1, 2011, 8:46 pm, in reply to "Re: BMW Mini 2004 - SRS light on, code OB #"
Peter Rainsley

Sorry for not getting back on this, but been away over the week-end. Is the isolator the whole box of tricks attached to the positive terminal, or just part thereof? I will look in the BMW archives to see if this enlightens me
many thanks for the responses,
Peter

Re: BMW Mini 2004 - SRS light on, code OB #

Posted by Shaun Dale <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT2719' width='330' height='300' border=0 style='border:none;'> on August 3, 2011, 9:04 am, in reply to "Re: BMW Mini 2004 - SRS light on, code OB #"

Hi Peter,
Just to clarify a bit, many modern BMWs (all?) have a battery positive disconnect system using a squib to sever the battery supply under control of the SRS in the event of a crash. I've never changed one myself but I know they are replaceable as I've reset the codes for the local body shop after they have.
I would think you could disconnect the squib connector and put in a dummy resistor (suggest 1.5-2.0 Ohms) and see if the code will clear. If so a new unit will be required, if not then its hunt the wiring fault. Almost goes without saying but just in case, never continuity test the squib.
Shaun

Re: BMW Mini 2004 - SRS light on, code OB #

Posted by Peter Rainsley <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT5418' width='330' height='300' border=0 style='border:none;'> on August 4, 2011, 8:14 am, in reply to "Re: BMW Mini 2004 - SRS light on, code OB #"
Peter Rainsley

Thanks for that insight Shaun. I hadn't realised there was a squib built into the battery positive cable. So the code is referring to a high resistance in the squib circuit, not the battery cable per se. This I can best test by substitution. I will get some small resistors from Maplin. Mini are quoting £185 for this lead!
Peter

Re: BMW Mini 2004 - SRS light on, code OB #

Posted by Shaun Dale <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT2719' width='330' height='300' border=0 style='border:none;'> on August 4, 2011, 9:38 am, in reply to "Re: BMW Mini 2004 - SRS light on, code OB #"

Glad to help Peter,
It always seems to be the case with fault code descriptions that they don't check what they say is actually what they mean. On top of that with non-UK machines, descriptions that are written by a software engineer not a "hands-on" guy that are then translated by a translator who is unlikely to be english and doesn't understand the technical/colloquial nuances of english. The end result is often grammatically correct but meaningless unless you are familiar with the fault already. End of rant.
I use 2.5W vitreous wirewound resistors from RS Components. I use these because they are quite robust and the wire diameter is about right. 1R8 is stock No.294-2912, 2R0 is 294-2928 and 2R2 is 152-757 (there is obviously the full range, it's just that I've just bought these to fill in some gaps and they are still in their bags with stock numbers on! They come in bags of 5).
HTH Shaun

« Back to index

[ Garage Support ]

Copyright © uk autotalk