Hill Assist and ABS Lights ON

problem is with the Data Link
Backbone ABS Module or with
the J1939 Data Link from ABS
Module to J1939

 

I have a 2015 Freightliner Cascadia with a DD13 engine and DT12 transmission. The same issue that you described here happened summer of 2022. Every time the truck hits a pothole or dump, MIL, CEL, Hill Assist, Regen, ABS, and the red STOP lights will come on briefly. The engine will be still running, but the truck will be out of gear (no gear indicated on the dash). Brought to a dealership, they did a lot after treatment-related, such as replacing DEF doser, inlet NOX, and outlet NOX sensor. In the end, they replaced PT CAN wiring, and the truck was good for a few months.

By Spring of 2023, the truck got worse. The transmission would disengage even while driving on a highway with its cruise control set. The same dealership decided to lower the transmission, replace the split-pin bushing, replace the clutch, resurface the flywheel, and change the transmission oil and filter. The issue gets better, but still happens like a few times each day.

The funny thing is that it happens when you pull the truck off a traffic stop. In other words, it happens when you hard accelerate the truck. And most of the time, when the transmission disengages (no gear indicated on the dash), if you let go with your accelerate padel, the transmission will re-engage and will show a correct gear number on the dash.

 

Sounds like it might be the CPC