Airbag (and Intermittent Battery) Light - Code 986B

[EViS]

The red airbag light has come on our 2003 e85 with the following code coming up during a scan:

00 986B - SBSL: Resistance , firing circuit, thorax airbag, rear left (E85, E60, E61), or knee airbag, front left (E63, E64) too high

The following codes are also present and may be of relevance?

00 003D - GM: Boot-lid unlocking: mechanism
00 008A - GM: DWA alarm memory: passenger-comp sensor, front

I had a similar issue last year with fault code 987B. This was rectified with a replacement (used) SBSL module and the airbag light has remained off ever since. Additionally, for a number of years, the amber battery light will intermittently show for the first couple of minutes and then turn off. Could these faults be in some manner linked?

 

[enuff_zed]

Don't think those other codes are linked in any way.
However, given the issues a duff battery can cause I think I would be starting by looking into swapping that.
Hopefully your replacement SBSL hasn't died.

 

[EViS]

The very intermittent battery light is a pain and I've been waiting for it to throw a code, but none have surfaced that can be directly linked.

The battery is a shy less than 5 years old and still within it's Varta warranty period. I don't think it's at fault, but I am open to trying a replacement.

Also, worth mentioning that I can clear the airbag light and is stays off until the second cycle. The previously faulty SBSL wouldn't ever let me clear the light as it would immediately return on the first cycle.

Even prior to a replacement battery, is there anything else you may recommend looking at?

 

[bigwinn]

The very intermittent battery light is a pain and I've been waiting for it to throw a code, but none have surfaced that can be directly linked.

The battery is a shy less than 5 years old and still within it's Varta warranty period. I don't think it's at fault, but I am open to trying a replacement.

Also, worth mentioning that I can clear the airbag light and is stays off until the second cycle. The previously faulty SBSL wouldn't ever let me clear the light as it would immediately return on the first cycle.

Even prior to a replacement battery, is there anything else you may recommend looking at?

I had a similar code which was caused by the wiring in the door connector. Slight corrosion meant it triggered every so often

May be worth some electrical cleaner

 

[EViS]

I had a similar code which was caused by the wiring in the door connector. Slight corrosion meant it triggered every so often

May be worth some electrical cleaner

I'll investigate this, thanks for the tip. Is the plug that you refer to behind the door card and membrane?

 

[bigwinn]

The one in the door frame- where the electrics come out of the door and join the main car loom

 

[EViS]

The one in the door frame- where the electrics come out of the door and join the main car loom

That turned out to be exactly the issue, though interestingly the plug looked to be in pretty good shape, with only the slightest bit of tarnish on the pins. I also removed the passenger door card and gave the airbag connector a quick spray with contact cleaner, even though it looked spotless and probably didn’t need it. Code 986B cleared, and the SRS light hasn’t reappeared on the dash. Got to love an easy fix - cheers @bigwinn!

Before tackling that, I’d taken the Z4 to Halfords for a battery test. The report came back all clear, with the tester confirming both the battery and charging circuit were in perfect, "as-new" condition. Then, as a side note, he mentioned that the "low coolant" warning light was showing on the dash. Cue a moment of internal rapid cog spinning and mild embarrassment as I processed that comment. A quick online search comparing BMW coolant and battery warning symbols across forums revealed I’m not the only one who’s confused the two - some consolation at least . Another simple fix with a small coolant top-up and the light hasn’t come back since. Although I will keep an eye on this, having replaced the coolant tank and thermostat three years ago.

 

[bigwinn]

Always a pleasure.

That’s the good thing about the forum right…

 

[EViS]

Always a pleasure.

That’s the good thing about the forum right…

The forum always wins, right! Once again, thank you very much for the nudge in the right direction.