I have 160K on my late build 2004 6.0. I've owned the truck since it was new.

I own the AE scanner and bought it to help me resolve an IPR valve plugging issue which followed my recent bulletproof remote oil cooler installation several months ago. That remote cooler has been a great mod.

Before the oil cooler swap I had noticed a slight stumble in idle only when the truck was warm/hot, but it wasn't consistent. I had suspected an impending injector failure. It has been months since the oil cooler swap and the truck finally tripped a code: P0284 for cylinder contribution/balance on #8. Still inconsistent, but when the failure is there it will run more poorly at idle, and at high speed there is a noticeable drop in power, but it still pulls under acceleration.

Side note: I have all the original injectors except #6, which I replaced 3 years ago.

When restarting the truck the next morning to connect the AE scanner the truck started and ran normally. No miss and still no funky smoke. I connected the scanner and saw a nearly straight line on the balance test. I let the engine get warm, but noticed while waiting that the FICM power figures would occasionally blip to zero. it happens perhaps once every 30 to 40 secs. It may be the laptop itself with some stupid software running in the background. I'm not sure, but I have seen all three: FICM logic power, FICM main power, and FICM vehicle power blip to zero. Sometimes it is only one of these, sometimes it is two at nearly the same time, I've never seen all three drop at the same time. When the drop occurs I never notice anything in the engine idle performance. I would also add that so far the FICM shows SYNC'd throughout all this.

With the engine warm and finally missing, I was able to see the balance indication that points to cylinder 8. I'm planning on pulling the injector later this week, but would like to know if anyone has seen an AE scanner reveal FICM voltages like this? Is this indicative of a bad FICM or FICM relay or alternator problem? Additional side note: I have the dual alternator option.

thanks,
Greg

 

I would start by replacing the FICM power relay. I had random no start issues, cam/crank no sync codes, GP lite coming on, no off idle acceleration and would cut off after start/running for short periods of time.


Replaced the FICM power relay and that wen away.


Ed

 

Agreed, replace the FICM Relay. The relay seems to become sensitive to temperature as it ages which makes sense as it is a coil and contact device, it is worn or possibly corroded which you would not see unless you dissected it with a dremel

 

X3

The FICM relay is an easy and cheap thing to give a whirl. Something else you can look for on your AE tool is whether you are losing cam or crank sync when you see the FICM voltages fall off.

Of course, if you DO need a FICM, which I doubt at this point, we'd be happy to take care of you.

With the number of miles on your rig, though, there is logic in considering yanking both of the alternators to have them bench tested to ensure that both remain a-okay. Several have opted to do the conversion mod to switch over to a single larger Leece Neville to avoid any issues.

There's a link to the how-to write up on our Leece page. https://m.facebook.com/groups/1479494649003220?view=permalink&id=184025276626073 8&src=email_notif#_=_

Hope this helps!

Ed

 

I will check the crank and cam sync relative to the FICM sync next. if there is loss of sync with those does this point to the FICM or to those sensors?

By the way I forgot I had a new FICM relay on hand I'd purchased some time ago and had sitting on a shelf. It took me an hour to find it and about 30secs to install it. Unfortunately there was no change with the new relay--oh well.

 

If you lose cam and/or crank sync, the issue is not the FICM but either the offending sensor or something else (harness, etc).

Ed

 

I connected the AE scanner this morning and pulled up the menu to look for the SYNC values for the crank and cam. I really only see a combined option for SYNC called the "CMP and CKP" So I'm assuming this is a value showing if those two sensors are in sync with each other. I started the engine and observed this value as well as all the FICM values including the FICM SYNC. Weirdly though I did notice that the CMP/CKP Sync would cycle repeatedly from SYNC and not SYNC'd. Is this normal? or possibly an issue with AE software?

 

I think it's an AE issue. Mine does the same thing, and I've found many other threads with people saying the same thing. Very dissapointing since it makes the pid kinda useless for diagnosing.