GM3 questions

[76R90S]

03 540iT, 136k miles
I've been having trouble with intermittent rear door locking and hatch soft close. Research here (thanks edjack) and other places leads me to suspect the GME. I've pulled my current one and it shows it being a "High", part number 61.35-6 942 047. Other markings include HW 2.5 and SW 3.2.
New ones are going for $600+.
I've found some on eBay for less (mostly) than $50.
I've found that early models of the GM use mechanical relays and later models are Solid state. I don't know which models have which part numbers. For the most part all part numbers start with 61.35-xxx. The used ones I see on eBay have wildly different HW and SW numbers.

So my questions are: Do the part numbers matter after the first 4 digits? Do the HW and SW numbers matter, and if they do are higher numbers better, worse or do they even matter?

Thanks again

[haolibird]

Having same problem...

I yanked a GM out of a later model, mine is a '99, I pulled an 02, in hopes that it will solve my problem of rear window/hatch not unlocking.

I have yet to try it.
Hopefully, this weekend.

[76R90S]

A couple updates:
At ESC Tuning the new unit with my exact part number is $437.

Scott has a great resources at https://www.bmwgm5.com/GM3_Connections.htm and https://www.bmwgm5.com/GM3_Part_Numbers.htm

I've sent an email to Scott with my issues. If it looks like something he can repair, I'll use his service.

I'll let you know how that turns out.

[crazy4trains]

Scott has repaired a couple of my diamond keys. Totally satisfied. Good luck and let us know how it works out.

[76R90S]

Scott has repaired a couple of my diamond keys. Totally satisfied. Good luck and let us know how it works out.

That's good news. Thanks for the input.

I'll let you know what's up when I hear back.

[76R90S]

In my rush to get the GM out (which went really fast the second time) I pulled all the connectors before removing the neg lead from the battery.
What are the consequences?

Thanks for helping this idiot.

[JimLev]

?? I’d put the GM back in and see if everything works as it did before you pulled it.
Then open the trunk or door, wait 16 min for the lights to go out, then disconnect the negative lead.

[76R90S]

?? I’d put the GM back in and see if everything works as it did before you pulled it.
Then open the trunk or door, wait 16 min for the lights to go out, then disconnect the negative lead.

Jim, thanks for the reply.

I pulled the GM to send it off to Scott to have it repaired. I was wondering if there would be any consequences as a result of not having pulled the neg lead before I removed the GM.
If I put it in after the repair and everything works, what would be the point of removing the neg lead after it's re-installed?
Of course (I say now) I would remove the neg lead before re-installing the repaired GM.

[76R90S]

I got my GM back from having Scott repair it (https://www.bmwgm5.com/GM3_Repair_Service.htm). I put in the mail from NM on a Friday, before noon. Had it back by the next Thursday.
I installed the repaired unit and now my rear door locks consistently lock and the soft close on my hatch has worked flawlessly the few times I've used it today.
I spent way more time researching the problem than actually working on my car, but it was worth it.

FWIW, in my hurry to send off the GM3, I forgot to pull the negative lead on the car battery before I pulled the connectors from the GM.
When I got the repaired unit back I remembered to pull the neg lead, installed the repaired unit, reattached the neg lead and happy surprise, no codes or anything.
I think I just go very lucky.

Pull the neg lead before pulling the GM!!!

Thanks everyone for your help!

[bdiefAZ]

If your car has the original alarm siren, it's a good idea to either, remove it, replace it with new unit, or replace internal batteries in the unit. The siren contains 3 rechargeable batteries that go bad over time, especially since our cars are 20 years old. The dead batteries can affect the locking system as well as drain the main car battery - Hope this helps.

The siren is located behind the passenger rear wheel liner.

[76R90S]

Brian, thanks for the tip. I'm not sure if the alarm is original, but I did notice the sound is very very weak. I got another siren from someone parting out a car but I did not know about the internal batteries. I'll check it out before installing in the 'new' one.
Thanks lots.

[dohalloran]

QUOTE: The dead batteries can affect the locking system as well as drain the main car battery - Hope this helps.

QUOTE: The siren is located behind the passenger rear wheel liner.

So access from outside the vehicle ? I have the fuse pulled for my alarm system. I've had some sort of parasitic draw (comes and goes) for the longest time.
So if the fuse is out, would that not negate a possible issue with these dead batteries affecting the locks and rear soft close feature ?
Just replaced the battery with a super strong AGM. Started having issues with electronics (as per normal!) whilst running a weak battery.

[bdiefAZ]

QUOTE: The dead batteries can affect the locking system as well as drain the main car battery - Hope this helps.

QUOTE: The siren is located behind the passenger rear wheel liner.

So access from outside the vehicle ? I have the fuse pulled for my alarm system. I've had some sort of parasitic draw (comes and goes) for the longest time.
So if the fuse is out, would that not negate a possible issue with these dead batteries affecting the locks and rear soft close feature ?
Just replaced the battery with a super strong AGM. Started having issues with electronics (as per normal!) whilst running a weak battery.

yes, from the outside of the car- remove rear passenger tire, then remove rear half of wheel liner fasteners to access the alarm siren. I have done it this way without removing the entire wheel liner.

[Nineline]

So my questions are: Do the part numbers matter after the first 4 digits? Do the HW and SW numbers matter, and if they do are higher numbers better, worse or do they even matter?

Were you able to find an answer to whether or not the part numbers matter or can any High GM3 be replaced with another High GM3? I'm having the same issues with my tailgate right now and my windshield washers though they are staying on if plugged in.

Thanks