GM LAN BCM, PCM messages 2015 Chevy Trax

[04colyZQ8]

Hey guys I cannot make heads or tails of out these logs I took from my vehicle all computers on the buss. Using GMLAN bible as that is the only real resource I could find. I am trying to find the RFA messages being sent from the RCDLR to BCM I want to add some code in the BCM to output to a relay when I press my non existent trunk button. I will get a fob from another similar year that has that feature as mine does not. Anyway from what I can tell from the GM LAN bible the address should be 0xb0 or 0xc7 I do not see them in my logs. in fact I don't see any addressing that makes sense I do not see 0x7e9 for pcm either? I do not see 0x640, or ox641 or even 0x40 for the bcm? I no not know how to tell what messages are 11-bit and which are 29-bit headers. And I cannot get the GM bible excel file I downloaded to open in my excel without many errors! If I try to manual calculate the the 11 or 29 bit header I don't find any arbitrary IDs that are listed in GMLAN bible. And it seems impossible to search for a arbitrary ID like 0x18 for battery module or 0xb0 for RCDLR, because you need to know the priority and then it is very difficult manually counting all the bits then converting to hex, easy to make a mistake.

Must be an easier way to do this? I would love examples from log files that show how to convert the headers to arbitrary IDs? GMLAN is from around 2009 did the GM CAN change from that to 2015? because my logs look nothing like their data: Note it doesn't help, that GMLAN Bible split apart the data into excel and didn't include raw logs, I have to guess what their data might have looked at before they put it into charts. For example:
0C 30 40 0 75 A7 8 // might be like this or bellow I'm guessing hoe it might have looked before it was put in a chart
0C 03 00 40 00 75 A7 08 // same as above but this might also have been what it looked like?

These are for battery module 0x18 and 0x18 is not even in their so I am really confused VPW is so much easier.
I am using a AVT-852 with Hex_term it is very slow and freezes up when monitoring all nodes. Maybe it is not reading messages correctly? Lets see some newer gm CAN logs if anyone has them.

I will attach mine.

traxconestoga_key on off .txt

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[04colyZQ8]

OK So I cannot find schematics for my trax but found some for the same part number BCM in a colorado/canyon. Looks like the BCM is the RCDLR so it just has an antenna directly into it. I might see the bcm still transmit a CAN message to or from onstar, because onstar can lock and unlock the doors. I suspect this would be over Single wire can (SWC) I do not have any way to log SWC.

I also think that is why GMLAN bible does not help me much. I thin 29-bit can is only used for 33.33 Baud SWC, and 11-bit is used for ISO can 2-wire 500 Baud. Currently I am monitoring only 2-wire. I am likely to only see pcm to transmission, and pcm to bcm messages on here I don't know that anything else really uses it? However I should still see messages from bcm to pcm for ign. on off, etc. But there is very little info on what 11-bit header addresses are for which node. WE know the PCM is 7e8, bcm is 641, but that seems to only be for service modes. Operational mode is different I need the vehicle access node 11-bit address.

[04colyZQ8]

what about a list of 2 byte nodes for 11 bit header CAN?
C9 = engine rpm

E9 or 0x3E9 ? speed?

[gmtech825]

PIN 1 LOW SPEED 33.33 Baud SWC HAS A COUPLE MESSAGES OF INTEREST. ID 24e000 SENT BY ONSTAR HAS BYTE ZERO, BIT 1 LISTED AS REAR CLOSURE RELEASE REQUEST.

ID 718000 SENT BY THE BCM, BYTE ONE, BITS 1-6 LISTED AS REMOTE FOB FUNCTION. A VALUE OF 17 SHOULD BE THE "Power Rear Closure Open Control"

YOU MAY ALSO WANT TO LOG 710000 AND SEE WHAT THAT DOES.

[Gatecrasher]

From what I've seen, the GMLAN bible is only good for pre-Global A cars. Even then it's not great.

The GMW8762 document has quite a few of the 11-bit Global A IDs, but there are still a ton that are platform and application specific that aren't covered. It doesn't have any of the 29-bit stuff.

Engine RPM is on 0x0C9. Byte 1, 16 bits long. RPM = x * 0.25

Vehicle speed for the driven wheels is on 0x3e9. Byte 0, start bit 6, 15 bits long. Speed (kmh) = x * 0.015625. Byte 0 bit 7 is a validity flag. It should always be 0.

An MDI can log single wire with the right software. I think you can also log with a normal CAN interface if you ground the low pin and set the speed to 33k.

The parts catalog shows a key fob receiver mounted to the windshield underneath the plastic cover ahead of the rear view mirror. There might be something you can tap into there.

[gmtech825]

also wanted to add that the rcdlr that recieves the signal from the fob has dedicated circuits to send the requests to the bcm so you won't find those messages on the can bus.

[04colyZQ8]

Thanks yes you are correct it has a dedicated signal from receiver to bcm.