FICM SYNC-Yes, SYNC-No

Fordracer · July 3, 2018

I'm working on a 2003 F-350 6.0 with 270,000 miles. After you drive it about 15 miles it starts cutting out and dying at times. Sync flickers from yes to no and the rpm pid is erratic when it's acting up. On demand code P2617 and continuous memory codes P0336, P0341, P2614, P2617. I ohm tested the crank and cam sensors from the PCM connector and they are good even when it's acting up. I back probed the crank and cam sensor circuits at the PCM and got the engine acting up and monitored the AC voltage. The voltage never drops out or acts crazy it just goes down with the rpm and comes back up with the rpm. I don't have a scope to check it properly. I wiggled the harness and it makes no difference.

All the harnesses I've replaced have never been heat related problems they just always acted up so I'm leaning toward a PCM but at $1,200 that an expensive guess. I've tried two other PCM's but they don't work with this truck.

Do you guys think I'm heading in the right direction?

forddieseldoctor · July 3, 2018

If the sync is dropping out like that you might have a loose crank sensor tone ring. The 6.0 timing tool on the ids will show it the easiest. Otherwise you can pull the oil pan and see if the ring moves.

Fordracer · July 4, 2018

What and where is the timing tool on the IDS?

Can you reach the ring with your finger through the CKP sensor hole to see if it's loose?

forddieseldoctor · July 4, 2018

The timing tool is in the osciliscope menu. You have to have either the vmm or vcmm to use it.

The one that hotline helped me diagnoise a few years ago I could not tell anything through the hole but the osciliscope pattern was off. The repair would have been a short block and the guy got all bent and told us we were full of shit and his buddy was a diesel tech and he says that could never happen.

The first picture I borrowed from the timing tool pdf file located under the service tips tab on pts. It explains exactly what it is supposed to look like.

The second picture was what mine looked like. I was off a half of tooth and it was enough to give me weird intermittent lack of power and cause the sync pid to switch when the concern was present.

Edited July 4, 2018 by forddieseldoctor
Found me pictures from the black hole.

Fordracer · July 5, 2018

I quit Ford over a year ago and am now semi retired and work in my own shop. All I have is a VCM2 and I have no access to a scope. I guess I'll either have to buy a scope or send him to someone who does because I hate to guess when the cost is so high.

Thanks for your input.

Bruce Amacker · July 5, 2018

I shot this when doing a class a couple of years ago at a major pump shop. The truck started off as an intermittent run problem with codes (I don't know which) and eventually turned into a no-start. I remember they had quite a problem doing diag on it.

Could yours be rust jacking of the sensor? I might monitor AC output from the alt or unplug it and see if the problem changes. Bad alts do weird things.

https://www.youtube.com/watch?v=3DWaR70feMc&feature=youtu.be

6.0_Powerstroke_loose_crank_reluctor.mp4

forddieseldoctor · July 5, 2018

Since you don’t have a scope I agree with Bruce.

Cam sensors are way more common to rust jack and it usually deystroys the sensor. At least in my experiences.

Fordracer · July 6, 2018

Bruce your You Tube video isn't working.

I did unplug and unbolt the alt wires with no change.

Does the crank sensor have a problem with rust jacking? I've heard of the cam sensor doing it but I've never seen it around here, I'll look at the cam sensor tomorrow. I did put a used engine in this thing a few months ago and it might of came from a rust state.

Bruce Amacker · July 6, 2018

I've not heard of a CKP rust jacking but that doesn't mean it can't happen. If I were headstrong about fixing this truck I'd change both sensors and overlay (or replace) the harness. Don't cross the wires as they are polarity sensitive, it will run but run funny.

Years ago I had a 7.3 that did weird things because of a bad CMP harness. Using a scope I proved that the harness bled voltage from the turn signal wires into the CMP circuit. I disassembled and inspected the wires to see no damage or issues, and as an experiment put polyloom over the CMP wires, which fixed it. Looking back I obviously should have replaced the harness but the fix worked and the driver was a cheapskate. I knew the guy and the truck was fine years afterward.

Does the video work through DTS?

I changed the YT from Private to Public, it should work now.

Fordracer · July 7, 2018

Yeah that video works. I didn't realize both links were the same video.

Thanks for all the input but he's taking it to a place that has a scope to check it out. It's kind of weird that this is the first diesel I've ever turned away but I can't justify buying a scope at this point in my career since I'm coasting into retirement. I'll let you know what fixes it.