View Full Version : CM850 Support

Orange Stroker
December 22nd, 2017, 07:16 AM
Do you plan on supporting the CM850 in the near future?

December 26th, 2017, 02:40 PM
We will be working our way back to the older ones once the dust has settled on the more current ECM's.
Probably the CM870 and CM875 will not be done as they both use Cummins 'old' comms spec, I think the CM850 was the first of the newer comms spec we can talk to.
But they will be many months off, don't expect anything in the first quarter of 2018.

November 19th, 2018, 05:29 AM
Any Update on the CM850s?? I've got one I need to tune before spring time.

We will be working our way back to the older ones once the dust has settled on the more current ECM's.
Probably the CM870 and CM875 will not be done as they both use Cummins 'old' comms spec, I think the CM850 was the first of the newer comms spec we can talk to.
But they will be many months off, don't expect anything in the first quarter of 2018.

November 19th, 2018, 06:26 AM
So I can get the file to read, but after the ignition time out when I go to save the file I get a pop up that reads
"Efilive has detected unknown changes in the file that is being opened. Invailid chip address."
Has anyone else successfully read out a cm850?

November 19th, 2018, 08:41 AM
Dominic, are you using the current public release here:

We've had a few CM850 reads sent in so yes it does work.

November 19th, 2018, 11:13 AM
I did try with the latest public release but I forgot to update my firmware. I'm going to try and read it out again tomorrow with the updated firmware to be sure. I'll send in the read when I get it.

November 19th, 2018, 12:35 PM
No problem, thanks Dominic. Please keep in mind we don't actually offer editing for this ECM at the moment, people are either using EFILive to flash existing tunes in or editing the file outside of EFILive.

November 19th, 2018, 12:45 PM
@GMPX do you have an ETA for file editing with Efi-Live? I don't plan on tuning the truck until the spring, I just wanted to read the file out and get started before the boat is put up for the winter.

November 19th, 2018, 04:01 PM
None of these older Cummins ECM's will be put in the current V7 software, they are waiting for the V8 editor which currently is in limbo for a variety of reasons. At a guess maybe Q2 or Q3 next year perhaps.

November 20th, 2018, 01:44 PM
I sure hope it's out sooner than later. I would much rather use your editor than Calterm.

November 22nd, 2018, 10:02 AM
Dominic, it's been an interesting exercise with the CM850. Unfortunately with this ECM it looks like it has been evolving since its introduction in 2002, the result is the ECM structure between the initial version and later CM850's like your one is very different, it might as well be a different ECM it is that different.
I think I have resolved the problem with the reading failing at the end for you however we still need to work on checksums for all the variations of how this ECM is structured. The ECM we tested with here is from 2005 which still used the structure the same as the initial 2002 version which is all working fine, I don't know when they changed but yours is the later style which we still need to work on.
Hopefully next week we can get an update done that will allow you to read this ECM successfully.

November 22nd, 2018, 03:30 PM
It is interesting to see how much it's changed. Not sure what the trace file tells you but this specific ECM is for a QSL9 that's in a Lobster Fishing Boat. It was repowered in 2016 with this engine, being new at that time. When I plugged into this boat I was really surprised to see that it had a CM850, being that the engine was so new. I was expecting to see a 2350 or something.

November 22nd, 2018, 04:30 PM
I think it is one of those ECM's that does the job just fine for off-highway applications so they just stick with the cheaper and simpler (and by now, proven) option.
The trace was good enough that I could see there was some big differences between our bench CM850 and the one you were trying to read.
I've been able to accommodate for two varieties of this ECM layout but there is a third that is going to be a real challenge, however I think that is the industrial applications version (generators, pumps etc).
Next week we should be able to release an update that will get yours reading ok but we will still need to make some changes to display the ECM summary and checksums when done. Sorry you've ended up 'beta testing' but we really had no idea Cummins had made such a drastic change to the ECM and not given it a new name (eg, like CM2150D transformed to CM2150E).


December 22nd, 2018, 07:06 AM
I was working on a forklift with cm850 yesterday. I tried to get a read and couldn't. I was not using latest software release though. I also tested for any supported scanner functions and nothing was supported. I'll update and retry next time I see the machine.

January 28th, 2019, 11:04 AM
Any update on this? Summer is coming up and would love to be able to flash some Marine Engines. Would be even better if we had editor support!

January 28th, 2019, 12:22 PM
I did redo the CM850 files in the hope that it would account for all three configurations this ECM comes in when trying to read.

But if the read is successful the software still will not understand the checksums etc for your variation of the CM850. Annoyingly we need to get an actual read to be able to configure this.
I had asked around a few tuners I know to see if they had later year CM850's lying around but nobody did, latest I got was 2005 like my ECM here.
According to the calibration history your calibration W90571.0x was released in 2008 and uses the ECM P/N 4921776 like my 2005 which is very odd indeed given the differences.

I feel bad asking you to get back out to that engine just to try a read again when the file still will not be tunable at this stage.
I might try to somehow force your calibration in to my ECM.....what could possibly go wrong :grin:

January 28th, 2019, 12:34 PM
What could possibly go wrong.. haha. I will get to the engine later this week or early next week. I'll send the file then.

January 28th, 2019, 12:36 PM
Thanks Dominic.
Just looking a bit closer I just can't see how the later file you are trying to deal with could possibly work in my ECM, I best leave it I think rather than brick mine.

February 7th, 2019, 08:44 AM

Above is the read from the ECM in question.
Thanks for the help.
Best Regards,

February 7th, 2019, 09:36 AM
Thanks Dominic, there is good news and bad news. The good news is the read all appears to be fine, the bad news is this OS appears to be configured very differently to other CM850's. I am going to have to make more changes to the software so this file will open in V8 for you. I think after this change everything should be good to go with this file.
All this comes about because it would appear this code was transitioning between their older ways of doing things and how later ECM's like the CM2150, CM2250 are, this OS sits like a mix of the two methods.
Sorry I know this is annoying but we'll get there, unfortunately we can't pre-empt what we might come across out in the wild with Cummins.

February 7th, 2019, 09:47 AM
Of coarse! That's understandable. Living in Maine we've got a ton of Lobster boats around and the QSL and QSB's are very popular. I should have a read from a QSB 330 over the next week or so. We'll see what that ecm has to say.
While looking at the Cal ID from the QSL it's like a P2I file or something, I'm having a hard time figuring out how to get that file to open in Calterm. It's not like the later ecms that's for sure.
Thanks again for the help.

February 7th, 2019, 11:17 AM
P2I is the engine ID.
It would have been nice when Cummins made these transitional changes if they changed the ECM model name too, maybe from CM850 to CM850B, or CM851 etc.
Unfortunately the older style CM850 (released around 2002) and the new style CM850's (still going to this day) share the same part number, same ECM ID etc yet are very different when it comes to the code internally and mapping :bash:

February 11th, 2019, 04:33 AM

Here is another QSB read. This is from a 355hp 5.9 Marine Engine. I'll paste the OBD read as well below.

Description Value Units
Engine Control Module #1 (ECM1)
Description CM850 Cummins HD Diesel ECM
VIN *****************
ECM Name CM850
ECM Part Number 04921776
ECM Serial Number 34251833 (last 8 digits only)
Operating System 15010011 (last 8 digits only)
Calbration ID Z90095.08
Cal Verification Number $FFFFFFFF
Engine ID E2I
Engine Model *****************
Engine Serial Number 46528616

February 11th, 2019, 09:44 AM
Thanks Dom, should have an installable update very soon with all this CM850 stuff sorted out.

February 11th, 2019, 12:15 PM
Did that last file that I posted have the same issues that the previous file did? Just curious if it was a marine thing with the 2mb flash.

February 11th, 2019, 12:53 PM
Sure did, it was in fact the exact same operating system as the other file.

February 11th, 2019, 01:37 PM
Didn't even notice that! That's pretty interesting being that one engine is a 9 liter and one is a 5.9..I know the calibration is different but figured that they would have different os being such a spread on engine size. I should have a couple more reads over the next few months.

August 5th, 2019, 03:36 AM
Is the 850 editing support dead for good??

August 5th, 2019, 08:43 AM
No, but it is not going in to V7 for editing, it will have to wait until the V8 editor is done (as we all four other HD ECM's of this era), sorry.

August 5th, 2019, 05:17 PM
Hope it comes out any soon. I wouldn't even mind beta testing it'll save me the hassle of an entire ecm swap and stuff

May 6th, 2020, 05:17 AM
Hope you all made it through ''hide from Covid lockdown'' fine.
Just popping in to see how V8 editor is coming for the CM850. I'd love to be able to use this fancy tool for more than Reading and flashing.

May 17th, 2020, 06:47 AM
I'm on the same page here. I've got a handful of QSB and QSCs at the shop that I would love to start playing with.

May 17th, 2020, 10:04 AM
The CM850 is an interesting ECM, spanning from about 2004 through to 2013 the software has changed considerably from something like an early Dodge ECM to what was running the 2012 Dodge.
I'll admit we have not started mapping them still as we are focussed on supporting the existing platforms in V8 first but when we start I don't think it will be too hard as it all looks quite familiar.

May 17th, 2020, 03:02 PM
[QUOTE=GMPX;251991]The CM850 is an interesting ECM, spanning from about 2004 through to 2013[/QUOTE
They still using the CM850 in 2019 on Fecon skidsteer.

May 18th, 2020, 08:08 AM
Wow, that is a good run.

September 25th, 2020, 05:35 AM
I have a 2020 tree schredder here with a QSB 6.7 with than ECM.