How do I figure out if its the 2 byte or 5 byte? Its not giving me any numbers under the seed.

i think i seen type 11 in the ecu address id. or 18 i think 11

Where do you see that?

If you have the Utility file you can check if its 2 or 5 Byte, but seems not have Security access

On 5/19/2025 at 4:41 PM, Beezer said:

How do I figure out if its the 2 byte or 5 byte? Its not giving me any numbers under the seed.

You need to put an algorithm in there otherwise it won't output anything. Try 0x29, that's from a 2019, it might be the same. Put that in the box, do a read info then it should give you something back in seed/key.

I retreived the SDM calibrations of this vin, and uses table 00 and algo 00. try it in DPS to see if drop a seed/key

No all GM modules has a security seed and key. If DPS list no seed, it means the module is not locked and doesn’t need security access.

10 hours ago, Troy said:

No all GM modules has a security seed and key. If DPS list no seed, it means the module is not locked and doesn’t need security access.

In this case, their DPS is broken.

10 hours ago, Troy said:

No all GM modules has a security seed and key. If DPS list no seed, it means the module is not locked and doesn’t need security access.

Something's up with DPS on it, I have the same module and was pulling a key no problem

18 hours ago, Troy said:

No all GM modules has a security seed and key. If DPS list no seed, it means the module is not locked and doesn’t need security access.

I have the same SDM, their version of DPS we've found is good. It's a bench setup and looks like it's not happy with something. They were trying 83.3kbps but I said to step down to 33.3kbps. At that point, the SDM is responding with "Conditions not met" after the security access request seed. I'm pretty sure it's unhappy with being on the bench, possibly not having enough inputs connected or something. I've downloaded the CALs for that one and mine, our utilities are the same and I can get a seed from mine. Also, this one uses one's compliment instead of the 0x29 that the newer Sierra's use. DPS would just give the wrong key back though if 29 is entered.

I've got another SDM here wired through a BCM and I still can't communicate with the SDM properly to change the vin.

ProgramLogtest.Txt

Here are the pinouts for the sdm and bcm. I am on the high speed data through the bcm to the sdm. Am I doing something wrong?

BCMX1Document ID_ 4240087.pdf BCMX3Document ID_ 3954336.pdf BCMX6Document ID_ 4240105.pdf BCMX7ocument ID_ 4240109.pdf SDM1Document ID_ 4240056.pdf

I got it! Wired wrong. Thanks for the help!