No FICM SYNC intermittent

Looking for some tips/experience.

One of the trucks that we did the full "bullet proofing" as they like to call it. Truck had heads/headstuds/oil cooler/ etc all done.

Now the truck intermittently cranks very long. Finally got the customer back and got the truck to duplicate the concern. When the truck is cranking long, the FICMSYNC pid is reading NO, then will change to YES and truck will fire right up. ICP pressure is doing well.

Truck has new cam sensor already. RPM reading seems good, even while it is cranking and not starting.

Also, when engine is cold it seems to always fire up well. When hot it is very intermittent.

FICM voltages are good.


Any thoughts?

thanks!!

FICM issues most likely

FICM sync is the communication between the FICM and PCM. There are dedicated communication wires between the two. Have a look at those, especially check the connections at the FICM to make sure they are properly seated.

Thats what I was thinking. Must have some resistance somewhere or a bad connection. I'll take a look. thanks.

When the FICM logic board fails, it is common to lose sync