Need a little help with CANBus trouble.

[BattleTank]

So is the CAN down or not? If it is that's why the truck is not starting and you're gonna need wiring diagrams. First step is to check ohm's with a volt meter at the Obd port to see if the CAN is intact. I'm not sure what the correct ohmage should be and what two ports you need to check but you can find it out pretty easily with some research. Pine Hollow Diagnostics on YouTube has some pretty good videos on CAN troubleshooting.

KEY OFF ENGINE OFF, Check resistance of CAN H and CAN L. Should equal about 60 ohms.
KEY ON, ENGINE OFF, measure voltage CAN H to GRND = 2.6 VOLTS DC-should be PIN 6
KEY ON, ENGINE OFF, measure voltage CAN L to GRND = 2.4 VOLTS DC-should be PIN 14

 

[BattleTank]

There are many videos on YT that shows you how to use a cheap 2 channel oscilloscope to watch the network.

Being a Volvo tech, our big trucks can have as many as 14 modules on the CAN network, having a good working knowledge of how it works is crucial.

 

[petethepug]

Hahaha, CANBUS = 56K modem technology wired with tinsel thin phone wires.

Perfect comparison of a peanut butter & jelly classic