Airbag light on - no error codes

[ferrelscent]

Hi all,

My airbag light is on. I took the z to local independant (not a bmw specialist). He plugged in the box for diagnosis,....but under the airbag section no error codes were reported. Then he tried the engine management system section and it 'would not connect'

They did not charge me...and suggested I go to an independant bmw specialist. I've phoned one and booked it in...but the bloke on the phone sounded very confused about the situation as I described it as though he had not heard of such an issue before.....so not very hopefull of resolution.

Has anybody got any ideas what steps I can take next ? or experienced the same ?

Cheers.

 

[sk93]

If there's someone near you on here with the INPA software, they should be able to help.
Else, you can invest in a B800 diagnostic reader from amazon (about £15) which will give you the airbag error code (but not clear it).
Any indy that offers bmw diagnostic should be able to read and clear it for you tho...

 

[Marco]

Depending on your model of Z4, you may not have an airbag ECU, it may use satellites. My airbag error (on a 2.5i) was found under a different section (using the BMW INPA Software), I cant remember the name now. It is most likely to be a faulty "Occupancy Sensor Mat" or "Seatbelt Tensioner". I'll try and find out exactly which section it is under, but it definitely wasn't under "Airbag". As the message above, if someone near you has the INPA software, its worth checking in there. I have the INPA software and would be happy to assist but I'm down Farnborough (GU14) and will be away for about 3 weeks at the end of this week.

 

[jampudding]

My AUX fan was running on full blast from the moment I turned the key on till I turned the car off, and I don't use AC. While I was trying to diagnose the problem I decided to disconnect the coolant temp sensor wire. I then turned the car on and found that the AUX fan did not run but the Airbag light had come on. As the AUX fan runs for a period after you turn the car off I assume the connection to the coolant temp sensor must be hot (connected directly to the battery). So when I disconnected the wire to the coolant temp sensor I should have disconnected the battery first.
In an attempt to clear the fault I bought the B800 tool, but got no fault codes displaying and thus could not clear the light. Anyway it was time for my MOT and the car failed - my mechanic gave me 2 options 1. try and find the reason for the Airbag light or 2. He will just clear the light (ps. he said it was not showing any fault from his diagnosis). This morning I picked the car up and guess what no airbag light!! I'll see how long it lasts - but he did say to me he would just disconnect the light bulb if he could not clear it.
Capital Cars in Raynes Park. I live in New Malden if you want to try the reset tool - I have little faith in the tool.

 

[ferrelscent]

Thanks for replies. Not sure what box/software local garage was using ..mighr already be what you are recommending. Will see what independant bmw specialist reckons.

Fan comments are interesting cos Im sure this issue came up only since i took car in for radiator fan wiring fixing.

 

[ferrelscent]

Update - took it to independant bmw specialist and their box picked up the error.

 

[foxy-stoat]

Update - took it to independant bmw specialist and their box picked up the error.

What was the error - faultly satilight box or air bag?

 

[THECATMAC]

Great.....no answer on this one? I have the same issue...

 

[srhutch]

Great.....no answer on this one? I have the same issue...

Doesn’t mean the answer is the same though. You need a better code reader by the sounds of it to determine the issue.

 

[portculisz4]

Has similar problem and on forum advice I bought +C310 scanner. The problem showed both as undervoltage on the airbag section and as a fault on the SBSR (Satellite B-Pillar, right) section. Cleared both faults and so far problem has not re-occurred in about 50 miles driving. Still suspect an intermittent contact problem somewhere so advice on where I should be looking first would be appreciated.