Truck has been slow to start and sometimes took a few tries to get it to fire up. On monday the Truck would not start. The FICM was not getting sync. I figured it could be a bad connection to the FICM. I pulled the FICM, cleaned the contacts and reconnected it. The truck fired up. It ran all day Tuesday without incident but wednesday morning it would again not start. Again what was missing was FICM sync. This time disconnecting and plugging back in the FICM did not fix the problem. I have spent the last two days troubleshooting and am out of things to try. I want to find the problem before I start throwing parts at it so I am turning to the hive mind for help. Thanks for taking time the help out.

The problem as it stands right now

The truck will crank but not start. Scanner says it has oil pressure, a steady 48v (FICM has new power supply). The IPR sits around 50% when cranking at 1200psi. However, the FICM will not get sync. I have worked my way down and tested both the Cam and Crank sensors from the PCM. The Crank sensor has a resistance of 360 ohms and produces a AC voltage of 500mV when cranking. The camshaft sensor produces 100mV AC when cranking (camshaft sensor was replaced as the original produced AC voltage seemed low 20mV, new sensor produces 100mV). I have tested the camshaft sensor at the sensor and at the PCM connector. This has lead me to believe both the cam and crank sensors are ok and their signals are being probably transmitted to the PCM.

I have tried to check the inputs to the FICM to confirm the signals are getting there. I was unable to find a good pin out diagram for the 2004 FICM but what I found told me the crankshaft was pin 5 and the camshaft was pin 10. When cranking, pin 5 (crankshaft) did not produce a signal and pin 10 (camshaft) had a 200mV DC signal. Despite searching I have been unable to find what the input signals to the FICM should be.

Right now I suspect bad wiring between the PCM and the FICM, or a bad PCM. This is based on having good signals to the PCM, but (what I think may be) a lack of crankshaft pos. sensor signal to the FICM.

I am specifically looking for what the crank/camshaft pos. sensor signal at the FICM should be, as well as confirmation/disconfirmation on the diagnosis of bad PCM or PCM-to-FICM wiring

Truck Details
Ford F350 King Ranch 2004 6.0
Truck build date 11/18/2003
350,000 km
Studded
New FICM power supply
Stock truck; don't run any tunes

 

getting rpm readings when cranking?

What is your battery voltage when cranking?

 

I get about 100rpm when cranking and the voltage drops to around 11v. I replaced batteries and alternator four months ago. I have the batteries on a charger right now just incase however, when not under load they read 12.45V.

Thanks for your help

 

Batteries seem a little weak. May want to double check that they're all clean & tight. Including the grounds.

 

Thanks for the input. Soon as the batteries are charged back up I will check all the ground connections.

 

Truck wont start at 100 rpm. Won't sync at that low rpm. As long as you see an rpm value, you most likely have a good crank sensor.

You need 150 rpm to start.

Load test the batteries individually after they are charged. Reading battery voltage is not a proper way to test batteries. You need to test amperage capability (not just volts).

 

I agree with mark get the crank rpm up


if it still don't want to play after that then we could dig up info on sync and cmp/ckp sensors but it must spin Faster to start with

 

Thank You for all your input. I got the batteries charged up and took them to get load tested. They came in well with in spec. Got them back and installed, engine RPM is back up over 150. I am guessing I discharged the batteries while cranking the truck over the last few days.

With the fully charged batteries it still would not get sync. I did a lot more reading online and keep coming up with the wiring harness as the most common cause of crank no start no sync on 2003/2004 trucks. I found no chaff on the loom and had a close looked at the areas mentioned in the tech folder to be common areas of chaff. Unsure of how to diagnose of a bad connection I read one article on line to crank the truck wiggle of the loom. I had someone crank (only in shorts burst I don’t want to have to replace the starter) and I wiggled different parts of the loom. I checked the FICM connectors by pressing them up into the FICM. As I pushed the back one
in the truck started. Releasing the connector would not cause the truck to stop running but when trying to start the truck will not get sync unless the back FICM connector is pressed in.

My solution to this was to wrap some big zip ties around the FICM which put pressure on the connecter. It seems to be working but as a permanent solution I don’t like it. What is the move now? Do I replace the whole wiring loom or is there a way a to just replace the connector?



Thank you so much for all your help

2004 FICM with zip ties holding in back connector

 

You can buy just the FICM plug that you need (the plastic tabs break). The downside is that you have to pull the pins out and then insert them in the new plug. Not complicated, just tedious. It is cheaper than a whole new harness though. I can get you a part number (others can too) if you want to go this way (I don't have my parts list available at the moment).

There is a thread about using a piece of 3/8" fuel hose as a "spacer" that will flex and keep pressure applied to the FICM connector and keep it plugged in. A search should locate it.

This is better than the zip ties as the zip ties tend to wear bare spots in the wire insulation over time.

 

Thanks Mark

If at some point you can send me the part number for the connector I think I will go that way. I would rather fix it right then mess around with other ways of jury rigging it. No rush on the part number I won't be doing anything with it till monday.

 

FICM connectors:

C1388C (X-3, to/from PCM). X3 is a wider plug than the other two and is nearest the degas bottle:
AP0018: 1456315-6 or X-3 (without wires) or AP0031 (with wire pigtails)

C1388B (X-2, Inj 2,3,5,8). This is the middle plug:
AP0019: 1456315-2 or X-2 (without wires) or AP0032 (with wire pigtails)

C1388A (X-1, Inj 1,4,6,7). This is the end plug:
AP0020: 1456316-1 or X-1 (without wires) or AP0033 (with wire pigtails)

AP stands for Alliant Power
Diesel Equipment Company :: AP0020 FICM CONNECTOR

 

Thanks for passing this along. This is super helpful.

Has anyone found a good source for the complete wiring harness? I am wondering if it might be worth doing the whole thing?

 

I would go w/ a Ford part on that.

You can join FordParts.com and pick AutoNation at White Bear Lake as your primary dealership and get very good prices and reasonable shipping.

Also, Ed at FICMRepair.com can get you good the part at a good price as well.

I believe the part number is 4C3Z-9D930-AA for a late 04; 3C3Z-9D930-AA for an early 04

$233.50 from FordParts.cpm (plus shipping)

 

Awesome! Thanks

 

Ouch - didn't see that you are in Canada until now. Not sure how to get things to you at a reasonable price.