On 2023 Peterbilt trucks with VECU architecture, what is the SA 39 for?

[RSoms23]

Need to know PGNs that may be broadcast with SA39 and it appears SPN 245 (VD) / 917(VDHR) may be having that SA.
What other functions do VECU ECM support?
Is there a diagram reference available (besides the Body Builders Manual?

[ben.martins]

Hello,

Unfortunately I don’t have any information other than what’s available from the body builders instructions I’ve found on the internet.

The best way to determine what PGN’s might be present is to capture CAN data with Pico using the J1939 serial decode guided test. This will allow you to then filter out messages with SA39 and from there determine the PGN’s present.

Appreciate that’s not really the answer you were looking for. Maybe someone has more information to offer.

Kind regards

Ben

[stevesauerland]

SA 39 is the VECU2. Primary = 39, also = 17, 44, 49, & 50 Primary = 0x27, also = 0x11, 0x2C, 0x31, & 0x32
Have a whole spreadsheet with ECU source addresses from Paccar that would gladly share. The VECU is the cab controller with integral central gateway module. With addition of the VECU and internal gateway module, the "Y" cable or crossover cable was no longer needed to comply with HD OBD standards for scan tool connection.

VDHR relates to Vehicle Distance High Resolution. Fault code 917 for VECU are all hardware/software faults with no T/S information provided from Paccar.
The isobus.net site is great for looking up SA's, SPN's and PGN's https://www.isobus.net/isobus/sourceAddress
Hope this helps someone.