ACSM battery safety terminal issue.

AndyD33 · Post by **AndyD33** » Fri Mar 16, 2018 8:28 pm

Alright chaps, right having a few dramas been away for a few months and on my return came back to a dead battery, anyway thought no drama replaced it as it has never been changed. After putting in new battery noticed airbag light on dash, I’ve run diagnostics with Dis-v57, INPA and Rheingold and cant delete issue it is my understanding that being a safety issue I need to resolve before deleting error.
Any suggestions as everything seems to point to a new battery cable.

https://www.imageupload.co.uk/image/EF1t

Ducklakeview · Post by **Ducklakeview** » Fri Mar 16, 2018 8:34 pm

The BST (battery safety terminal) has a double sheathed cable, it has a thin aluminium layer that is terminated at both ends of the car and monitored by the ECU's. If the connectors at either end become detached, it detects this and flags up a code. There are small and thin wires with spade connectors on at the battery and under bonnet positive terminal ends. I've seen this once, and it also turned the airbag light on when one became detached.

Mike

Ducklakeview · Post by **Ducklakeview** » Fri Mar 16, 2018 8:36 pm

It CAN be bypassed, but you obviously lose the protection in the event of a massive short.. https://5series.net/forums/diy-do-yours ... ss-125288/

Mike

AndyD33 · Post by **AndyD33** » Fri Mar 16, 2018 9:42 pm

Cheers Mike just had a look, I actually have some of those resistors I may see if I can attach it tomorrow without cutting the cable, just need this sorted for MOT as it’s due Monday and then I’ll look to replace the cable I’ll update this providing it works.

Ducklakeview · Post by **Ducklakeview** » Fri Mar 16, 2018 9:50 pm

AndyD33 wrote: ↑Fri Mar 16, 2018 9:42 pm Cheers Mike just had a look, I actually have some of those resistors I may see if I can attach it tomorrow without cutting the cable, just need this sorted for MOT as it’s due Monday and then I’ll look to replace the cable I’ll update this providing it works.

I'd check those little connectors at either end, that's how I fixed the last one. A new cable is from memory, about £400 - So I can't imagine even a breaker only wanting £50 for one..

Mike

AndyD33 · Post by **AndyD33** » Sat Mar 17, 2018 12:09 pm

Right attached resistor, cleared codes. The BST error has gone but still have the following two

Battery lead, positive (monitoring of Shielding)
Battery lead, ground (monitoring of shielding)

AndyD33 · Post by **AndyD33** » Sat Mar 17, 2018 2:00 pm

Ok quick update, after reading many articles I decided to completely follow all the cables from the battery, all seemed ok in the boot of the vehicle, I then moved to the front of the vehicle to the battery connector point, I almost missed it but there’s a singular wired that was broken so I repaired that, ran a scan, deleted error codes and problem sorted.

It appears as though the battery change was just a mere coincidence and that the problem was the little wire.

Image of wire - https://ibb.co/cGdNUc

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