[dieselnoob1]

Hi All ---

Just picked up another 6.0 --- 2006, 195k. Seller said it didn't have power on the highway and that he was told it needed a new FICM...

Brought it home and hooked up my edge insight to test drive for awhile. What I am seeing is this:

P0299 - low turbo boost. I'm getting some boost but what doesn't seem like a lot. The last owner said he only used the truck in the summer, so I am thinking the turbo just needs a good cleaning or at worst to be replaced?

My bigger concern is the following however:

99% of the time, the FICM voltage is 47v-48.5v while driving. However, almost everytime when I start it cold, a couple of minutes after starting, the FICM will drop down to 43v and slowly climb its way back up to 48v. Battery voltage is solid (13.9/14v), and this drop does not correspond with the glow plugs drawing power. (Battery voltage is high when the the FICM drops). The drop in FICM only lasts for less than 30 seconds, but I am curious as to why.

As a corollary, I recently got a P0278 cylinder #6 contribution balance code. Truck ran fine the whole time, not rough, no smoke. Could this have been triggered by the brief low FICM voltage? Think the FICM is on its way out?

Any insight appreciated!

 

[dieselnoob1]

Small update... Took her for a spin this morning and noticed that it only does this when cold. The FICM voltage varied between 43v-47v until the truck warmed up, then it is consistently 47-48, even when turning off/re-starting....


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[TKOPerformance]

At 13.9-14V you are not reading battery voltage; you are reading alternator output. I would start by disconnecting and load testing each battery individually. If they are anything but perfect replace both batteries. What you are seeing is the battery voltage being dragged down by the glow plugs when the truck is started. The alternator doesn't start charging until after the GPs go out, so the batteries are depleted, and the input voltage to the FICM is not what it should be, its trying to make 48V, but it can't create voltage from thin air, so the FICM voltage is low. The problem is that is putting a lot of strain on the FICM, and will eventually lead to its failure.

As far as the other issue, it sounds turbo related. I would start by cleaning the turbo, as well as the EBPS and tube. Check the unison ring to make sure it isn't egged out on the actuator hole.

Also check those hot side CAC boots, they are probably overdue for replacement. Clean them thoroughly, squish them almost flat, and look inside. I'll bet you see a lot of white lines indicating cracks.

Its also worth inspecting the wiring to the TVCS, sometimes it gets hot and can fry the insulation and short out causing improper vane position.

 

[dieselnoob1]

Thanks TKO...


I pulled the batteries and I am going to get them load tested.... in the meantime I swapped in the good batteries I had in my other '06 (which has been running fine). I cleared all the codes and have been driving it for a few days and the only code still being thrown is the turbo boost.

Safe to assume that it is a battery issue and not a FICM one? The old batteries are only from Aug '14 and they are Bosch. I know that doesn't always mean a lot as people can trash batteries by running them dead too much... I just don't want to drop $300 on new batteries only to find out I need to drop another $300 at FICMrepair.

Thanks again!

 

[TKOPerformance]

Seems like it was the batteries. If they are from '14 you should have a substantial warranty left on them. Even without a receipt the place you purchased them should be ale to look them up based on serial numbers.