Airbag ECU replacement

[georgebest]

Replying to an old post cos this problem is just getting more and more common - I also have a 2000 E39 540 with an internal error 240, initially only below about 8C but eventually warmer.

Things I learnt ;

1. My original is v2.5 MRSZ3/A.
2. A LOT of 65776900727 ecus have the internal error 240 already - I've bought a few off eBay and all were duds til the last one.
3. You can use a higher version number, but when they say "superceded" they mean "we also superceded every other part of the SRS system so unless you replaced them too, you're boned". If you have MRS3Z/A you can't fit MRS4 etc. The MRSZ4 ecu p/no 65776920848 sitting in front of me as I type is V3.6 and is free to a good home
4. Thinking the original problem stems from a dry joint caused by the alloy housing stressing the PCB when it contracts and expands (mine only failed under 8 degrees celcius) I decided I had to (a) buy from a HOT location, and (b) get the HIGHEST version within my ORIGINAL part number, which from what I could see was the v3.0 I bought from California - it worked great!
5. My usb odbc connector (under bonnet) did not detect ignition in INPA so I fixed it with the jump wire. At one point I thought the cable was my problem and bought a prettier one that also didn't show ignition only this time I didn't bother fixing it, and it coded just fine so don't worry if INPA doesn't show a black dot for ignition.
6. I used the standard Expert Mode, not Revtors - probably makes no difference for straight coding, I just figured since I don't want to edit the TRC and upload a MAN I'd go plain vanilla
7. NCSExpert won't run on 64-bit, but happily runs in XP mode. The first cable I bought came with two DVDs and a brilliant installation and "Launcher" app which totally took care of all of that for me.
8. Here's a summary of what little I learnt of part numbers ;

• 65776900727 - mine 1/3/1999 onwards (newest I found was v3.0, which I bought)
• 65776910676 - 1st supercession 1/1/2001 to 26/9/2001, V3.5, I think this is NOT compatible with MRSZ3/A but can't be certain
• 65776920848 - 2nd supercession 29/8/2001 to 12/4/2002 V3.6, got one, can't code it as it's MRSZ4/16SB
• 65776919789 - 3rd supercession 25/2/2002 onwards V3.7, fair bet there's no chance in hell this'll work with my MRSZ3A bags etc either

This is the first DIY I found and you are a life saver, thank you!!!

Geoff
Wellington, New Zealand.

Followed Geoff guide, got a 65776900727 with 2.5 software from Ebay (a new one). It came off from an E39, I used it in my E38. Interestingly, no coding was needed. Once I put it in all errors cleared and the check light went off. Quite amazing!
Also, coding with BMW Scanner worked but not perfectly, although I could change the VIN it still showed E39. This was easily address by coding with NCS Expert (SP Coden writing), it has changed it to E38. Probably didnt matter much but since it's considering safety I rather did it properly.
What an amazing feeling driving without the checklight on! I also bought another module as a backup for $30, they are getting really cheap on Ebay. Compare that to the list price of $1300 https://www.ecstuning.com/b-genuine-...t/65776900727/

[riverjamie]

Spirit force, first thanks for posting. I think I also need to replace my AirBag Module on my 2000 E39 528i for F0 INTERNAL CONTROL UNIT FAULT. ALSO CODE 11 POWER SUPPLY. Only shows Airbag at start-up, then restart car light goes away. Replaced weak battery (needed one anyhow 8 yrs old) and did bypass for Occupancy sensor did not help. Tried clearing those codes but they always come back. So my feeling is the Airbag module is no good. Now my real question. If I pickup a used ebay one, same part number and version, and from the same model and yr as my car can it just be plug and play? If not, do you know if the Vin has to be coded into the replacement module? Did you have to send yours to a Airbag reset service that I've read about online? If so which one did you use? Thanks again

[Chedley]

You should be able to reset and code the used airbag module with NCSExpert...

[balidawg]

I've always wondered if you were to open these up and hard-reflash the EEPROM firmware back to stock (would need a known-good to read from...) if you can fix the problem, or, if it indeed is a hardware failure. I have an internal error one down in the basement, I should try it sometime.

If you read the EEPROM and disassembled all the code that does the self test, then you could identify your specific failure. But, my guess is there’s a whole list of checks and the first one that fails does an early exit from the routine with an error. Folks who have poured over the DME code could probably infer what types of checks the self test does.