Need Help! 2006 E350 SMB


New member
This is a long post. Sorry for being long winded, but I would greatly appreciate any insight to help us resolve our problem.

My wife and I have a used 2006 SMB based on the E350 platform. We have had it for about 8 months with no real issues. Recently we began having problems starting the engine. The engine turns over as if it is about to start, but never does. This issue has left us stranded in Death Valley...not once...but twice in the last month!!

The 1st time this happened in DV, we had our truck towed to Las Vegas. The Ford dealer confirmed that car would not start. He then found that the ground terminal which attaches to the frame was loose. They tighten it up and the car starts up. We come back to pick it up several days later and the car starts on 1st try. We think it is fixed.

We head back home to Northern California and figure we'll finish up the Death Valley trip which was cut short the 1st time. No issues the first day we are there. However, on the 2nd day we experience the exact same issue.

We take the truck back to same dealer and he looks at it again. Car does not start initially and then one of the techs starts shifting around the engine wiring harness. Voila! The engine starts right up! So now the dealer says that the main engine electrical wiring harness needs to be a tune of $4k!!

I ask them are they sure this is the solution to the problem. They say no.
I ask them if they were able to isolate to a specific circuit. They say no.
I say that I am not comfortable with their analysis and need a more thorough diagnosis before authorizing repairs. They are not willing to do further analysis.
I then have the truck shipped back to Norcal.

The truck is now at a Ford dealer here in NorCal, but the car now starts so they are having a difficult time identifying the issue. Batteries are new/strong, fuel injection strong, oil pressure strong...everything looks good.

The only common link between the non-start is that we were on traveling on bumpy roads prior to the non-start event (think road to Scotty's Castle which is being graded/gravel and the road to the Devil's Golf Course). Roads with lots of vibration.

Has anyone had/seen/heard of this issue before? What was the solution?



As weird as it sounds what about the battery terminal connections? I have a 01' E350 and in the middle of nowhere wouldn't start. I popped the hood, checked the terminals, tried starting again and bingo! I only bring it up because you've had diagnosis at a dealer so figure it's something weird or obscure.

You say it's a SMB but has SMB checked it out? Could it be the battery charging system?


New member
Thanks for the reply. It is something we can look in to ourselves. We asked the dealer to check and they confirmed that the battery terminals we're fine. We should verify.

At this point SMB has not checked it out but we have talked to them about the recent events. That may be the next step if I can not find support locally



Does it happen when the engine is cold or when warm. I had a similar problem with my 2005 F250, which I believe you may have the same 6.0 PSD engine and it turned out to be a bad ICP sensor.


New member
The 1st time it happened it was a cold start. We were at a campsite from 6pm( or so) to 8am the next morning.
The 2nd time it happened we were in a campsite from say 7pm to 9am. Started fine in the morning...we drove about 7 miles to a tourist attraction where it was parked for 3-4hrs. Did not start when we went to leave. Not sure if that is considered a cold start or not.

Thanks for the feedback on the ICP sensor. I will ask the mechanic to check on Monday.



That's how mine was. Wife only drove it for about 7-10 miles and then it sat while she was grocery shopping, came back out and would not start. Had to leave it there for six hours before I could get it to start and drive it home. If I remember right, the temps were around 40-50F that morning when she drove it. It generally took just enough drive time/running to get the engine warm enough and then it would not start if you tried within 15-30 minutes. I would have to let it sit for several hours to cool back down again. The sensor if i remember right is located on the passenger side of the engine on top. It's alittle bit bigger than a standard spark plug. Very easy to replace yourself.

Hope this helps.


I am well in tune with the 6.0. There are a few things that the dealer should done.....but possibly did not. They need to data log the start.....both hot and cold . The hpop need to generate 500psi at the inj in order for the truck to start. Here are a few of the failure points....leak in high pressure oil system to enclude fittings and o rings ..... Next is the most common which is batteries.....they might show 12v but they need to be healthy enuff to spin the motor to generate the psi needed to fire off the motor....anothe is a week starter . If it is a true electrical problem ck the ecu primary harness that clips and screws I to the ecu..... Those are problematic and do come loose if some has tampered with them in the past and didn't seat them properly. Hope that helps


White Turtle Adventures & Photography
My daughter had similar issue on her car, would not start, then would. A couple weeks later it did not, and would not. Took it to guy she bought it from and he found the ground bolt / nut was rusted. Replaced with new and larger and problem fixed.

May not be same thing but is a quick and cheap thing to try.


Expedition Leader
It's the main engine harness. Very common problem. They are not well protected in key areas and will wear through the wire jacket and short. The clue is the shifting of the harness by the dealer causing it to start or stall.
It's the main engine harness. Very common problem. They are not well protected in key areas and will wear through the wire jacket and short. The clue is the shifting of the harness by the dealer causing it to start or stall.
Brad is correct, I'd bet money on it.. Needs a engine harness. Cost ~$900 for the harness and a lot of patience and time to r and r.. My bet specifically on the no start would be cam or crank position sensor leads as they snake down between all of the accessories and the engine block and cook.. ask me how I know..


We do a lot of engine harnesses, but equally ICP, and it could also be a HP oil issue. Don't guess, get it diagnosed before you dig in. Intermittent no starts are a ***** to fix. If you were in Orange County I could hook you up, I have a Senior Master tech who rocks at Diesel issues. We work on tons of SMB and Earth Roamers. If you want to talk with my tech call my cell 949-289-0099

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