Help! My 06 6.0 won’t crank or start

I was driving on the highway, and out of nowhere, the truck just gently shut off. No loud noises, no jerking—just turned off. The “Check Gauges” light came on, and now it won’t crank or start.

I also noticed there’s no communication with the OBD port. The tow truck driver did something—he unplugged something and connected it to the battery, and the truck cranked but still didn’t start. Any ideas on what’s going on?

Check all the connectors at the PCM and FICM. A loose or bad connection there could cause this.

When you turn the key on, do you hear the injectors clicking?

Roux said:
When you turn the key on, do you hear the injectors clicking?

No, I don’t hear any clicking.

Jody said:

Roux said:
When you turn the key on, do you hear the injectors clicking?

No, I don’t hear any clicking.

Start by checking the three plugs on your FICM (it’s on the back of the driver’s side valve cover). If you have access to a scan tool or know someone who does, it would help a lot to read live data. You need 48 volts on the FICM. Also, you can run an injector buzz test. Those FICM plugs are known to have broken retainers, and they can wiggle loose over time.

@Roux
Even if the FICM plugs were loose, I think it should still crank. But it’s worth checking.

@Roux
I was going pretty fast on the highway when it happened, so I’ll check the FICM plugs. Does it matter that I recently had the cylinder 3 injector replaced?

Jody said:
@Roux
I was going pretty fast on the highway when it happened, so I’ll check the FICM plugs. Does it matter that I recently had the cylinder 3 injector replaced?

That shouldn’t make a difference. They wouldn’t have needed to touch anything that could cause a no-start issue. Still, check your fuses and connections at the ECM and FICM.

It sounds like it could be a blown fuse or something with the ignition or PCM. The tow driver probably jumped the starter using a wire near the passenger-side battery. That won’t start the truck unless the ignition is working properly and in the “on” position. If it’s a manual in gear, it could roll, so be careful!

@Davin
Thanks for the tip. I’ll check the fuses and see if that’s the issue.

Check the plugs on the FICM, the IPR valve screen, and any other connections. If your OBD port isn’t working, that’s the first thing you need to fix—it’s impossible to troubleshoot without it.

If you’re on a budget, get a Forscan dongle. The app is free, and it’s a good diagnostic tool for the 6.0. Owning a 6.0 pretty much requires a scan tool.

Do you know what the tow driver unplugged when he was messing with the battery?