06 No start, No can bus after engine build

[SixOhh]

06 auto truck was down for about a year for a big build.

Upon attempting first fire up i start adding the puzzle pieces together...

-The air dog wasn't getting signal from the trigger wire. I had to jump the relay to get fuel circulating. After several crank cycles i realize we have fuel at the rail, but no power to the injectors..

-Plug in EFI to find no CAN BUS connection / cannot comm with vehicle.

-After some time under the truck i find 2 ground wires that were only hand tight after the motor install.... the ground from the ECU to the drivers motor mount and the main ground from the battery to the block were barley hand tight.
...cleaned and tightened both connections and nothing changed.


Did we brick the ECM trying to crank it with loose grounds?

The only thing i am going to do before ECU shopping is pin out the main supply voltage to make sure i am seeing proper voltage.

any other suggestions?

 

[tylerltr450]

I think you are on the right track. Pin for voltage and then ground. Check continuity of ground.

 

[Mark Nixon]

I have a hard time thinking loose grounds harmed the ECM.

Did you guys have any severe electrical storms in the time the truck was disabled?

If you end up needing an ECM, I may have one around.

Mark.

 

[SixOhh]

You were correct mark.

Ended up going over more wiring and noticed the gang harness above the valve cover wasnt snapped in all the way. Whew,

She fired right up smooth as glass with 200% overs

 

[Mark Nixon]

It's the simple things that can make your day, right?

Glad you found the problem!

Mark.