Need help!! Freightliner with Cat 3406e got me stumped

Ok gotcha. Will check it first thing in morning.

Ty

 

Ok

So i have 4.8v when key on at pin 36. That should be the coolant level sensor output voltage.

Now what?? Lol

 

I guess that means the ecm is turning on...just not communicating with the truck???

 

Update:

My trucks 40 pin plug has no j1939 connections made from the factory. Pins 36 and 33 have blank plugs in them.

I have j1922 and j1587 connections at pins 3 (.9v) and 9 (3.1v) and pins 1 (.8v) and 7 (2.8v) respectively.

 

I hooked my laptop with cat et to the dataport in cab and it connects just fine. I can read codes and see cslibrations etc...

I apologize but dont know tge difference between j1922 and j1587 how do i cjeck those??

The truck will crank...just no start and no CEL / ecm power on lights on dash