If you have a zapi program and a test lead you can connect right to the controller and see more errors than the dash display will show and the hour it happened. These trucks usually shut down when a steering error occurs setting the brake. I have seen several mechanical problem in the steering gear boxes causing intermittent problems.

you sure on that serial number?
it comes up as a bad number in my MCF Parts program but that doesnt mean it's a bad number, my database is outdated and it may not be in there.
just curious.... :o)

i also found a HPK document about steering system blink error codes that steer controller will show , if you can catch it in it's error condition maybe you can see what code it is showing?

One other tidbit of info that could be useful is you can press the enter key on the far right button under the display and it should take you to the info screen, then you can choose history and see what kind of faults this unit has been having and what hours they occured at. There will be 16 codes stored in memory.