I just reinstalled my FICM on Monday after a rebuild by FICMrepair.com and have had no problems until this afternoon. I climbed in to start up after a brief stop and it was doing nothing but cranking. Key off, sit there looking puzzled and try it again. Long crank time and finally fired off. While running it doesn't miss a beat, runs like a new truck. Drove it home and had to take it out again about an hour or so later and the same thing but I had pulled up all the FICM pids on the scangauge before trying the start. It did the same thing. All looks normal with the exception of the "0" next to the FICM sync. It started again on the second very long crank but as I was cranking there was no sync up until I tapped the accelerator pedal slightly. It switched over to "1" and fired up. I have never paid attention to when the switch over takes place and am wondering when that happens normally. Is it at key on, key to start or when the engine finally catches. It has been firing off after half a second of crank until today and now its taking a good 5-7 seconds of cranking twice in a row. Is it something in the FICM or am I just unlucky enough to have an independant problem starting to show up. My mind tells me to stroll down the road leading to the FICM having just reapired it but I want to try and diagnose this logically so anybody with ideas I'd love to hear them.
Eric

 

Im thinking it is unrelated as it showed up after trying to start it while hot. How does it start after a long cool down period? What are the ICPV's at KOEO? Should be .18-.24. What is the ICP pressure while cranking when its not wanting to start? And what is the IPR% while idling hot?

 

I went out and pulled some numbers. Scangauge said coolant temp was still at 162* so not really cooled off. ICV was sitting at .23, IPR was 14.4. FICM sync showed 0 as expected. In an effort to get numbers for you on the crank no start it fired right up after the usual half second and like I said it was still sitting at 162*. Running at idle I'm getting 583 on the ICP, 22.5 on IPR and .82 on ICV. I don't normally have these up on the SGII but they appear normal to me if memory serves. When it fired off the FICM sync immediately went from 0 to 1 the second the starter hit the flywheel. Any ideas from what these numbers show. I'm fairly good with the wrenching and hands on stuff but the electronic side of this engine has me offering up prayers that nothing goes sideways in that area.

Thanks
Eric

 

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Those numbers are spot on, watch those numbers in every time you attempt to start it so you can catch it when it doesn't want to start as that is when those numbers will be important. Also double check the FICM connections to make sure they are fully seated.

 

If it continues to act up you may want to watch cam/crank sync (labeled as just SYC) during long crank. I think FICM sync requires that input first and then syncs the injectors back to that. Depending on what position the engine stopped at, it may take a full engine revolution for the PCM to make sense of where the engine is at relative to #1 TDC. (Or wherever it references from)

SYC 07E02209CD 0462050906CD 3000 000100010000 SYC CAM/CRANK POSITION SENSOR SYNC (1= IN SYNC)
SYC 07E02209CD 0462050906CD 3001 000100010000 SYC ALTERNATE
SYC 07E02209CD 0462050906CD 3701 000100010000 SYC ALTERNATE

Also, make sure your scan gauge refresh rate is set to "fast" on the set-up screen.

 

program your scanguage to monitor RPM as well. I had the exact issue you had on my 06. Every once in a while it just wouldnt start. I was monitoring everything you are and I noticed Ficm Sync and Crank sync would show 0 until it started. After watching it for a while I finally noticed the RPMs showed 30-60 rpm on the scanguage while cranking. The starter and engine where turning over like normal it just wouldnt start. I finally tracked it down to a bad crankshaft sensor pigtail. The wires were bare and shorting out. I replaced the pigtail and sensor it starts every time now. Check both Crank shaft pigtail and Camshaft pigtail.

Good luck!

Daniel

 

Thanks guys. I'll try to get the CAM/CRANK sensor loaded into the SGII tomorrow morning before the first start of the day. Is there any under the hood things I could physically check. When I replaced the FICM I ended up replacing both batteries with new as well as putting two new alternators in (dual alt system). Might I have bumped something. I'll have to research where all the various sensors are physically located but if anybody knows of something that might share a wire loom with the alternator or other such thing I'm all ears. I had to disconnect one hose to pull the degas bottle aside as well, anything around that area I could have annoyed in some way. It acted up twice but has since fired up fine on the remaining four starts today. If anybody has a mile high view of what happens during a normal start sequence I would love to hear it as in...PCM sees ambient temp sets time of glow plug, key to start PCM looks at CMP and tells FICM cylinder one position, FICM syncs to CMP, etc. etc. maybe it's just all magic and aliens. Thanks for the help everybody.
Eric

 

I know the crank sensor is a pia... Its behind the a/c compressor. it ties into the loom with the compressor connector. The cam sensor is behind the power steering pump. all of them are fun to get too on this truck.

Good luck

 

I really appreciate the info. I'll take a look at those sensors and see if anything has gotten damaged. I'm hoping it ends up being something obvious once you see it rather than some irate electron running around.
E