No FICM SYNC intermittent

[bigfords]

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!!

 

[bismic]

FICM issues most likely

 

[IHPowerstroke7.3]

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.

 

[bigfords]

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

 

[bismic]

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

 

[Bahr]

Bit of a grave dig here, but I'm having identical issues. Did you find what it was?

 

[bismic]

Bit of a grave dig here, but I'm having identical issues. Did you find what it was?

Please post troubleshooting information (easily obtained with a goos and inexpensive scan tool like FORScan or Torque Pro):

Cranking data:
Cam/crank Sync
FICM Sync
FICM MPower
FICM LPower
FICM Vpower
Cranking speed, rpms
ICP sensor volts
ICP sensor pressure, psi
IPR % Duty Cycle

If the scan tool is a good one, scan for codes and post the code numbers.