zero volt ficm

[International350]

Had problem with my truck shutting off while driving. It would shut off, crank back up after 30min and a day later do same thing. Did for about 2 weeks now no start. Ficm is reading zero volts on all the 4 screws. Replaced ficm, all fuses, all relays, and still reading zero. checked the wiring and am geting volts to ficm. After reading FICm diagram it reads that ficm wont sync if crankshaft sensor is bad. Does that mean that it will register zero? any other thoughts?

[eabrust]

Originally Posted by International350

Had problem with my truck shutting off while driving. It would shut off, crank back up after 30min and a day later do same thing. Did for about 2 weeks now no start. Ficm is reading zero volts on all the 4 screws. Replaced ficm, all fuses, all relays, and still reading zero. checked the wiring and am geting volts to ficm. After reading FICm diagram it reads that ficm wont sync if crankshaft sensor is bad. Does that mean that it will register zero? any other thoughts?

International,

Sounds like a chafed wire somewhere, or bent pin on connectors, if you've been through all fuses. I don't believe the crank sensor is issue. By sync, they mean the FICM won't pick up timing in relation to the engine to fire correctly, but that won't prevent a power up, it will only prevent any injectors from firing.

As I follow the schematic, the first thing that happens at key on, is a 12V 'key on' signial is provided to the FICM. The FICM then must internally power the logic (make sure the FICM logic fuse is good), and then the FICM commands the MPR output ( which engages the main relay to power the FICM power side. Sounds like you are measuring the key on signal getting to FICM, but it isn't engaging the relay for main power?

I assume you've been looking at the FICM Guide pdf that can be found via googling (I'd attach it, but it's 5MB).

If your truck was intermittently dying, and then restarting after cool down, it could also be an internal board fault or solder joint in the FICM that is temperature sensitive (or was till it finally failed for good).

Good luck working it out.

Eric

[International350]

Hey thanks, yeah i have that big pdf file. The FICM itself is brand new because i thought the old one was bad, but still doing same with new one on. I looked for chaft wires but didnt see any. I will def look again a little more closely. Thats what i am figuring is that it isnt letting the main relay turn on. I cant figure out which wire in the FICM harness is the Mpr that relays back to relay so it comes on?

[eabrust]

Having any luck International? You could try manually grounding the one side of the FICM power relay to see if the relay itself is bad (it appears the MPR signal is actual applying gound for the relay, and the relay hot side is always hot).


I saw on another forum thread, that you had played with the 58 VDC mod a bit.

I've been running it a bit to, off and on (swapping in/out a couple FICMs), and just curious about a code I get running it. The FICM I did the modification to throws a P0611 code, but I get good running and a solid 57-58volts out of it. Did you get the same code while you ran it?

Just wondering if the FICM flags that code when voltage falls outside of a range (whether or not it is below or above range). I also did the modification to the FICM that has PHP tuning, so I'm not sure if the code is a result of the tuning vs the voltage.

Eric

[International350]

After brand new FICM an program, 8 new relays, and tons of sweat an tears, i just now got it running, it ended up being the MPR wire going into the FICM broke loose from the plug. It was in there so i didnt see it broken so i took all tape off and messed around an heard relay clicking on/off. soldered wire back in and all was good like nothing happened. Now i have to sell my other FICM since it works and i bought the new one from ford with no return policy.

The code, if its a Non Compatable FICM code then yes i got that one also. PHP and Swamps said its normal, its because the FICM has tuning on it that isnt the same as originally with PCM. I did run the 58v mod but didnt notice anything so took it off, especially since everyone on the diesel garage in swamps hot FICM thread were speaking about so many things needing to be built up in the FICM for longetivity.

I appreciate all your help, an if you come across anyone who needs a programmed FICM let me know.

[eabrust]

Glad you got it! Electrical gremlins are no fun, especially when there is such a bundle of wires in there.

Eric