2001 F250 7.3 cranks, fires and dies. won't run

[n448sj]

OK, I have gone through a lot of this forum and haven't found a problem quite like mine. I have an F250 7.3 4wd automatic. I have owned it since new. It has 130,000 miles on it and the only time it wouldn't start was a couple of years ago. I replaced the GPR and it fixed the problem. The truck has always run fine, it is not chipped, it's bone stock. A few days ago, I went to use it and it cranked over fine, popped off like usual and then immediately died. I tried starting it again and again with no luck. I will try to give as much info as possible because I know it's needed to troubleshoot properly. I was a certified mechanic myself over 30 years ago. Things have changed just a little bit since then. Anyway, I was really stumped because the truck has always been dependable. Then I got to thinking. I had it parked at the base of a 120' tower for my wind turbine. Later last week, a thunderstorm rolled through while I was gone, and my turbine took a lightning strike. I know this because when I got home later that night I had a diode blown out in the rectifier in the turbine controller. Also, I talked to my neighbor the next day and he told me he saw a big bolt hit my place. So, I figure that my truck got a tickle. (That'll learn me to park my truck so close to the tower) I did a little research on the net and then I got under the hood of the truck. First, I pulled the plug off of the ICP sensor on the driver's side cylinder head. I tried to start it and it ran but very erratic. I then pulled the plug off of the EOT on the back of the HPOP reservoir. I tried it again. This time it ran like normal. I took it for a drive of about 10 miles, no problems other then the SES light. I borrowed a Snap-on scanner from a friend a couple of days later and my brother showed me how to use it. When I first read the codes, it showed 7 codes. They were as follows: P1280, P0198, P0380, P0470, P1210, P1211, P0705. After clearing the codes and experimenting more, we decided that the ICP sensor was bad. I ordered one and put it on this afternoon. I reset the codes and tried to start it. I still have the same problem. Before I start buying more parts, I would like some input from someone more knowledgable and experienced than me.(it wouldn't take much) I went ahead and pulled the plug off of the EOT sensor and the truck started up fine and ran fine again. Still have the SES light and I noticed that the overdrive off light on the shifter was flashing when in park. If i put it in drive and wait a few seconds, it will stop flashing. When I put it back in park, it will start flashing again. I don't think that it used to do that. I checked the codes again after changing the ICP sensor and I got these codes: P0198, P0380, P0340, P0470, and P1210. With all of these codes coming up, I am beginning to believe that the PCM is messed up. I just don't particularly like the idea of just buying one without knowing that it will fix the problem. Any help or input would be greatly appreciated.

[klhansen]

Welcome to TheDieselStop

Here's the scoop on your latest batch of codes.

P0198
Engine oil temp. sensor circuit high input,
Open circuit, biased sensor, PCM short to 5v
That's why it ran when you pulled the EOT connector. The PCM went to default settings when the EOT signal went away.
P0380
Glow plug circuit malfunction
Open/grounded ckt., solenoid open/shorted, failed PCM
P0340
Camshaft position sensor ckt. malfunction
Open/grounded circuit, sensor fault, short to power
P0470
Exhaust back pressure sensor circuit malfunction
Biased sensor, open signal return
P1210
ICP above expected level
ICP sensor, open signal return

The stuff I put in bold could be your problem. The sensors share a common signal return, and maybe that lightning strike burnt a wire out. Check your wiring harness for toasted spots.

The fact that it runs when you unplug the EOT sensor tells me that your PCM is still alive. It's just getting bad information.

The signal return circuit is the grey/red wire going thru the 42 pin connector above the driver's side valve cover. You could unplug that and check continuity back thru each of the 3-wire sensors (EOT, EBP, ICP, etc). You might also want to check that same circuit from the 42 pin back to the PCM connector, although that one's a PITA to get at, down under the master cylinder on the firewall.

Good luck

[n448sj]

I want to give you a big THANK YOU up there in the Great White North. I read your post and started checking the wiring harness after work today. Turns out it wasn't lightning, it was hungry mice. It looks like they have been working on it for awhile. They chewed right through the copper wires. The damage was in the harness coming from the 42 pin connector on the driver's side valve cover. There was a spot down below the master cylinder about 6 inches long that was all tore up. I was able to disconnect the harness at the connector and I had to unhook 3 other sensor plugs ( brakes and air box) and pull it up to work on it. I called the dealer to find out the cost for this harness. All I can say is HOLY CRAP!! They told me it was over $1000! I think the parts man was embarrassed by the price himself. I told him that I could put up with a lot of frustration for $1000 and decided to try to patch up the harness. I got out some wire, my soldering gun, some heat shrink tubing and a roll of electrical tape. I was able to patch it up and get it all hooked back up in a couple of hours. Then came the moment of truth. I put the key in, waited for the glow plugs and she started right up. The SES light was off. I shut it off, hooked up the scanner and cleared the codes. Then I started it again, let it run a bit and then shut it off. I went ahead and checked for codes again and no engine codes showed up. I really appreciate your taking the time to write your post.
What I think is ironic is that I bought this very truck in 2001 to pull our fifth wheel up to Alaska and back and it turns out that's where you're at. We had a great trip and we plan on going back some day. We put over 12,000 miles on the truck during that trip. I'm sure glad we did it then, fuel was a hell of lot cheaper. If we go up again, we'll probably come up the coast on a boat and see some of the places that you can't drive to. I know there is a whole lot of Alaska that you can't drive to, it is like another whole country. Out of curiosity, have you been there your whole life or did you move there?
I was going to attach a picture of the damaged harness, but the file is evidently too large for this forum.

Thanks again,