Airbag Module Repairs, A1 Service For Code 240

[Chrisr1949]

Hi,
My year 2000 car's airbag warning light was on when I bought it. The fault turned out to be the clockspring or sqib module behind the steering wheel boss. Sadly I reconnected the battery with a front seat removed and created another error for the belt tensioner. I was totally blasé about this as I have BMW DIS diagnostics and thought that I'd be able to clear the codes with INPA. How wrong I was! The module had locked with a code 240, ECU internal error. You can read the codes recorded but can't clear them until the code 240 had been cleared. This requires the Eprom area of the airbag module to be accessed and cleared by a specialist. Code 240 is a software error not a hardware fault.

After much hair tearing (I'm 68 so lucky to have any left!) and internet searching I came across a company in Liverpool offering airbag ECU module repairs with a very quick turnarround. They've been going since 2004 and even at 8:30 on a Tuesday there was a knowledgeable tech available for an online chat. Because of the age of the module I had been refused by 2 similar UK companies but this guy assured me that they could do the job for me. They have a comprehensive list online of the more common ECU modules for which they charge £25 including VAT and return postage. However my module was not listed so their charge is £30.
I posted it to them on the Wednesday morning, they received it cleared it and posted it back to me on the Friday afternoon, I received it on the Monday morning and it has been fine. I refitted it and checked it for codes with INPA and there were no codes recorded.

The company is Crashdata.co.uk and I can't recommend them highly enough. They obviously have all the info for our older model cars. You have to send it to a box number as they protect their address details I suppose for the security of their premises and to discourage personal callers.

The module that I sent them was a Temic MRSZ3 V3.0 part no. 6908896. This module is apparantly ubiquitous for the code 240 error.

Here they are.

And finaly to remind eveyone of the airbag safety rules.

Before attempting any work on the airbag system:

1, Always disconnect the battery.
2, GO AND BREW UP! The airbag control module retains a charge for a few minutes, this is to power the module should the battery be disconnected in a crash. Make it at least 10 minutes AFTER the battery is disconnected before starting work. This minimises the risk of accidental firing of an airbag component.
Always handle the airbag system components with great care and remember what they are, "mini bombs" and store them in a quiet corner.
3, Before re-connecting the battery always re-check your work.

Hope this 'info can help someone out.

 

[mrscalex]

Fantastic price and service.

Definitely noted!

 

[Chrisr1949]

Yeah, I thought I was in for a much larger bill so I thought it was a good one to share

 

[Stevo7682]

Good that you found someone who has the knowledge and tools to carry out this repair and even better they don't have stupid pricing.
Company details noted .
Thanks for posting about this.

 

[Martin594]

Hi just found your post. I had the same 240 code fault and my local garage sent the airbag module 6908896, exactly the same as yours to a repairer in Liverpool (I'm guessing crashdata, but will confirm). The module was refitted, airbag light went off but came on the following day. When you refitted yours was there any specific to procedure to follow or was it plug n play. My garage has effectively said it can do no more to help. I'm left with no operating airbag and unsure on the best way to proceed.

 

[mrscalex]

Since this post was originally discussed (2 years ago) I've successfully copied configurations from a couple of non-functioning SRS modules to second-hand modules. It's pretty easy with the correct software.

These modules effectively self-destruct in the event of a crash and I believe physically burn some sort of fuse. So I think that's why they need to be sent for repair/resetting. But my experience is the configuration can be lifted still.

If the module is just faulty then the same applies. As long as the diagnostics can communicate with the module the config can be lifted.

 

[Chrisr1949]

Hi @Martin954, when I refitted mine yes the light came back on becase I hadn't yet fixed the fault that had caused the problem in the first place. Now you have had unit unlocked the fault code can now be read and the faulty airbag component can be replaced and the fault code erased. In my case it was the "clock spring unit" behind the steering wheel but of course the failure of any airbag component will cause this scenario. These airbag control modules do not go faulty but electronically lock after recording a maximum of, I think 65 errors. THIS CAN BE THE SAME ERROR RECORDED 65 TIMES. Every time you switch the ignition on it checks the airbag system and if it detects a fault it generates and stores a fault code for the faulty component. So when you've switched the ignition on 65 times there will be 65 instances of the fault stored on the module which cases it to "crash" and generate the code 240. Without unlocking the module it can't be interrogated to find out what the root cause of the fault is. So I'd go back to the garage and ask them to do an airbag module diagnostic and see what they find. That is unless a member of the forum is close to you and can do a quick diagnostic for you? I've found that it's only my old DIS diagnostics that will work reliably with my year 2000 car, my later Delphi diagnostics is unreliable on the earlier system on the Z, its great on my the later system used on my 2009 E91car. One very important point. If your car was built around the year 2000 it will have 2 diagnostic sockets, one under the dash which looks like the current ones and one a round one under a screw top cover under the bonnet on the right as you look at it. IT IS ONLY THE ONE UNDER THE BONNET THAT ACCESSES THE AIRBAG SYSTEM. The one under the dash only accesses the engine data. It was put there to pay lip service to new in 2000 EU legislation regarding the standardisation of diagnostic sockets and their placement on the car. I know that this has been a bit like "War and Peace" but I hope some of it helps. Chris

 

[mrscalex]

These airbag control modules do not go faulty but electronically lock after recording a maximum of, I think 65 errors. THIS CAN BE THE SAME ERROR RECORDED 65 TIMES. Every time you switch the ignition on it checks the airbag system and if it detects a fault it generates and stores a fault code for the faulty component. So when you've switched the ignition on 65 times there will be 65 instances of the fault stored on the module which cases it to "crash" and generate the code 240. Without unlocking the module it can't be interrogated to find out what the root cause of the fault is.

Great info this. I've bookmarked it.

 

[Chrisr1949]

Sorry, when I said the units don't go faulty I meant throw-away-faulty. I think most people would say it was faulty if it locked! What I meant was that they are repairable therefore avoiding the high replacement plus coding costs.