2000 F350 7.3 85000miles no mods except leveling lift.
I haven't been driving the truck much lately and it has been cranking a little slow but it always started. I went up to the mountains last sunday and was parked for a few hours got ready to leave and crank no start. Seemed to spin ok but not for long, so put it on jumper cables, still no start. Towed it about 100 yards hit starter to help with brakes, it started! Got home, next day start in am no start in pm? Charged battiers still no start messed with it tapping relays finally starts. Same thing next day am start pm no start. Put on new CPS , no go changed fuel filter no go, charger on and tapping around got start. Checked Forum and decided two new batteries seemd to be in order. Got two DH Golds and start up for me every time. Took it to dealer (they said it failed to start for them twice ) they say code P1316 and P0603, needs IDM at 600 dollars (friends cost) and PCM at 330 dollars (friends cost). Never had problem with this rig so I don't think I have a connector or wire problem at this time. Reading post here for two days seems like maybe the batteries the only problem? Had original motorcraft batteries. Can I trust this truck to start if I take it elk hunting?
Should I ignore the dealer recommendatioin?

Love this forum used it for long time to diagnose and fix other things but never posted before, truck has never not started before.

 

Hmm. I'm not sure what to tell you about those codes, but if it were me, I'd check the following:

Glow plug relay. Little brown relay, looks like a starter relay, sits near your fuel filter. If you cross the large posts with a screwdriver while someone else cranks, and she starts no problem, you've got a bad relay.

Battery cables. Seems if you are in there giggling stuff, this could be your problem. If you have dirty terminals or a cable that isn't connecting properly, it could cause starting issues.

Starter. You said the truck started after you whacked the starter? Crawl under there and take a look see, make sure you don't see any missing bolts. You may even want to remove it and take it somewhere to have it tested.

Edit. I have no manners. Welcome to FTE.

 

With the p0603 (keep alive memory) is normal if you have an aftermarket chip or programmer installed. You most likely don't need a new PCM. The code P1316 is definately for the IDM. A short in the wires going to the injectors will be the biggest cause for making an IDM go out. Have they checked ALL connections first to determine if you actually need a new IDM?

Where are my manners?

Welcome to FTE!

 

Keep in mind that you must have at least 10.5 volts to crank on of these things. If less the pcm will reset and idm will not fire. If tapping something helps, could be a bad connection somewhere. What ever relays you are tapping, look at the manual and see what they control. If it is a starting related circuit, the change out relay and see if that does it. Have someone to crank what you check voltage with DMM. If less than 10.5, either you have a bad alt. or batteries or both.

 

And welcome to that posting ranks!

 

I think the tapping was just coincedence, but we tapped the relays on top behind the fuel filter, one I think is GPR the other I am not sure (any one know) these are just off to the passenger side of the fuel filter and one behind the other.
I do appreciate all the input and advice, I have read so may post on here I know it is way better than any dealership, plus I have used this forum to rework my door locks and that went great. Diagnosed a friends truck via these post and it fixed him.

 

Original (possible) batteries in an '00 truck means that you got your money's worth out of them. Batteries that are a little weak (to Barry's point) will not allow these trucks to fire. Bad or dirty connections can do it too. Check the volts. That maybe all it is. The two relays that you are referring to on top of the engine are (front one is the Air Intake Heater - AIH - and the rear one is the Glow Plug Relay - GPR). The AIH has nothing to do with starting, the GPR may if it's cold out and the engine needs the glowplugs to fire up. Most likely it's your batteries.

 

Well it has been just about a week and no problems, I believe the crank no start is behind me. Thank you all for the help, I read a lot of threads on here that lead me to the batteries so I wanted to stay with that instead of going with the dealership expensive part. Thank you to all of you.

 

Sometimes it will crank and not start and drain the oil resivior for the hpop system. Check that if the problem reoccurs, should be within about 3/4 inch to the top of the resivior.