Truck died today and now I get absolutely nothing when I turn key

[damuddog]

I was heading down a long stretch of hill on the jobsite and I slipped the transmission into 2nd to let the engine do the work. I always do this on this downhill section. About 2/3 of the way down the hill the truck just shut off. When I came to a stop I tried to restart the truck and all the gauges start normally but when I turn to ignition nothing happens. Actually TCB error flashes on the readout while my foot is on the brake. When I ran a system check I'm getting an engine sensor error and a transmission temp error. I had the truck towed to the shop and the mechanic can't get the OBII scanner to read anything. I mean it is like it is not attached to the truck. He also started checking the fuses and found 1 blown it is I believe a 20 amp F2.22. When he replaced it and turned the key the truck cranked for a second then blew the fuse. Replaced with a 30 amp and it blew instantly.

What can possibly be wrong here? I/he/we don't know where to start right now.

[m-chan68]

That fuse supplies power to the PCM, GPCM, ICP sensor, fan clutch and MAF sensor. I would start by unplugging the fan clutch, and see if it starts.

[damuddog]

Update:

Started unplugging the various components on that fuse and narrowed it to the ICP valve sensor. Today I got the new sensor in $160. Installed it and the truck started up! Hurray it's fixed! It idled for about 10 minutes while I cleaned up and I jumped in to leave. I made it about 30 feet and it died. Same symptoms. WTF is with this truck???????

[NYC F-350]

Originally Posted by damuddog

TCB error flashes on the readout while my foot is on the brake. When I ran a system check I'm getting an engine sensor error and a transmission temp error

Those symptoms sound just like what I had when I had an issue with my FICM plugs. One was not fully seated/locked into position and I got the TCB error message on the message center on the dash and few transmission and transfercase codes.
Double checked the plugs (they looked good, but they were not) and made 100% sure they were locked, truck fired right up and has been running good ever since.
Just something to check, if you had been under the hood recently and had unplugged the FICM for any reason.

[HAM_RADIO_MAN]

Originally Posted by m-chan68

That fuse supplies power to the PCM, GPCM, ICP sensor, fan clutch and MAF sensor. I would start by unplugging the fan clutch, and see if it starts.

For sure, make sure the fan clutch didn't eat the wires!!

[damuddog]

Fan clutch wires are good.

[damuddog]

I'm really getting frustrated with this problem. The mechanic has spent the better part of a day and a half going over the wiring harnesses using a power probe smart transmitter searching for shorts. He has got a lot of false shorts from the transmitter but nothing positive yet. Every item on that circuit has been tested and the circuits probed. He's about to throw the towel in and send it to Ford. Any of you tech guys have any last ditch ideas? I've been without my truck now for 3 weeks.

[m-chan68]

Is that same fuse blown again?

[damuddog]

yes and now we get absolutely nothing even with that sensor unplugged.

[damuddog]

Well, the truck has been at the dealership now for 2 weeks yesterday and still no diagnosis. Last week they calledand said they unplugged the fan clutch and the truck started just fine. They plugged it back in and still ran. They took it for a test drive and all was good. They were scratching their heads because they had not really done anything. Out cam the schematic books and they started tracing wires. Nothing is reading on the code scanner. Yesterday they took it for a longer test drive to try and make it fail again and they succeeded. Now, like the ICP sensor, unplugging the fan does not work. I am out of warranty but they are offering me a loner truck tommorrow as a consolation for getting no where in 2 weeks (5 total for me).

I am frustrated beyond belief and somewhat heart broken at this point as I really liked this truck but feel like at this point if it ever runs again I'm just selling it.