What's involved in coding an MRS airbag module?

JobsonJadson · Jul 21, 2020

Hi, so my airbag light is on and I have my MOT coming up mid-August. Car is a RHD 325i with an M54, built in '03.

I bought a cheap k-can cable, installed the Standard Tools and ISTA+. I scanned the codes with ISTA+, had 35! historical errors. Deleted those and was left with 12 error codes, mostly relating to the Multiple Restraint System...

ISTA+ calculated a test plan and the first port of call is to replace the airbag control module. I've located the module and ordered a replacement, however I keep seeing that a new module will probably need to be coded to my car.

So here's my question(s), what does coding a module entail? Could it be done with NCS Expert? ISTA-P? Is it a matter of clicking a few buttons or is it closer to actual hello world coding? Do you need more sophisticated equipment than a k-can? ISTA+ was mentioning an ICOM and 70amp PSU. I'm presuming a PSU would bypass the battery and the airbags?

Sorry if these are noob questions. I'm just trying to understand the process better and figure out if it can be done at home to save money.

Much thanks.

NZ00Z3 · Jul 21, 2020

NCSExpert is the coding tool you need. I don't have the instructions for the job. Maybe if you do a google search, you'll find them.

Bali · Jul 21, 2020

This document covers coding an ABS module on an E39. The process is the same.

Bimmerforums - The Ultimate BMW Forum

Bimmerforums is the preferred online BMW Forum and community for BMW owners. At Bimmerforums, you will find technical how-to information maintenance specifics audio advice wheel and tire combinations and model specific details not found anywhere else. Our professionals are here to help make...

www.bimmerforums.com

.

MrMCar · Jul 22, 2020

FWIW (never done so professionally) a used SRS module of the same number/supersession will code up just fine on that car.
The module has the capability of 3 incidents.

Have seen such performed (used car dealer) multiple times.

JobsonJadson · Jul 22, 2020

Thanks all for your responses! Trying to get my head round that .pdf now 😅.

MrMCar said:
FWIW (never done so professionally) a used SRS module of the same number/supersession will code up just fine on that car.
The module has the capability of 3 incidents.

The module I bought is from the same run as the one in the car. But if I'm reading what you're saying right, do you think... IF the car still has a problem with the actual airbags, could it brick this new module right away?

Bali · Jul 23, 2020

Maybe you got lucky? Normally you need to code a used module after it’s swapped in so it knows your car’s particular options.
If the donor car had the same options maybe it’s fine? I’ve never swapped in an MRS module, so not sure how much coding matters on it.

AndyAnderson66 · Jul 23, 2020

Getting a used airbag module is cheaper than getting a new one but the module will still need to be re-programmed. This is because, when you install a different module inside your vehicle, used or new, you will need to program it to your VIN which requires a dealer in order to happen.

Bali · Jul 23, 2020

AndyAnderson66 said:
when you install a different module inside your vehicle, used or new, you will need to program it to your VIN which requires a dealer in order to happen.

A dealer is not needed to code a used module for an E46. NCS Expert does it just fine.

JobsonJadson · Sep 5, 2020

Just checking back in to say, my car got through it's annual test no problem and the light hasn't returned. Guess I got very lucky with the module. Would rather win the lottery, but I'll take it!

Thanks all for your help. Much appreciated.

Bali · Sep 5, 2020

Well done! Thanks for coming back and posting the solution.
See you soon....when the next issue arises. Hahaha

JobsonJadson · Sep 6, 2020

I've got a feeling that'll be pretty soon! Cheers mate.

What's involved in coding an MRS airbag module?

Bimmerforums - The Ultimate BMW Forum

Top Contributors this Month

Recommended Communities