Gm canbus speedo

I am using an obdlink mx+ with my ls swap. Unfortunately i have a gen iv swap with an e38 ecm from a 2009 suburban. I can not get the app on phone or my pi to pickup the vehicle speed. I have switched it between all the parameters i can find and cannot get it. Has anyone else had an issue like this?

I do see speed in other apps off the can hp tuners and obdlink on pc and phone but not realdash. So i know the device is broadcasting the info.


I think this is the one im looking for but cant seem to find it.

Here are our GM-LS XML files:

RealDash-extras/RealDash-CAN/XML-files/GM at master · janimm/RealDash-extras (

The frame 0x19d seems to contain transmission shaft speed and trans slip info. Speed should come in frame 0x3e9.

Seems like you do have to make your own custom XML file to match your setup.

The 3e9 doesn’t move at all on the can analyzer. I know that every thing reads on the older pcm. So does the pid possibly pull from somewhere else on the later model if so how do i find it? Like i said i can see speed in all the other apps i use just not real dash. Same with a few other pids like stft

You probably will see the speed on RealDash also if you use OBD2 connection, but direct CAN is a different beast.

Very hard to analyse remotely what would be the CAN address of vehicle speed on your ECU, sorry :frowning:

So are you saying to change the setting here?

If you are referring to that, it means to delete the entire connection and use OBD2 connection type instead. It will be a lot slower though.