OK I had a previous post about a dead truck. Codes were for EGR and glow plug control module. Truck is at the dealership. Manager said they have gone through a checklist and all the wiring, etc. is checking out OK for voltage, etc. They have deduced that the problem is the PCM being bad. does that sound right???? they called in to Ford to get the approval to replace it. Hopefully that has been some of my hard starting issues too.

 

Sounds like a load of crap to me. Out of the list of possible PCM communcation issues, the only code you listed relative to such a problem was the glow plug control module.

Like I said in the other thread, I would point to the glow plug control module itself. Symptoms of a bad module would include hard cold starts, no cold starts, and very smoky startup for the first 20-30 seconds of runtime.

 

the way the manager made it sound was that they checked voltage across the glow plug control module and it checked out O.K. They then deduced that it wasn't recieving the proper signal from the PCM or something to that effect. Ever since the truck blew out the turbo and oil pump last year I have had issues with hard cold starts and have had it in at least 3 different times for that without them being able to pinpoint that problem. The manager was feeling that this PCM was part of that problem too....I really don't know myself just passing on what they are saying and seeing if that jives....May be time to look at trading for an '06 or '07......buyout

 

Ask them to see if there was any record of the high pressure oil pump being checked after the failure of the low pressure pump. Particles from the failure of the low pressure pump can most certainly damage the high pressure pump given the right circumstances.

 

If I remember correctly they first checked the top end of the engine for compression etc. It was good. So then they checked out the high pressure oil pump and it was OK. Then they checked out a relief valve between the high and low end. It was good. they then checked the low end pump. the casing had a 3-4" crack in it and the inner gear was in about 4 pieces. they found some pieces of the turbo vane in that pump. They determined that the turbo was an older style with to tight of a clearance and went out. It shelled the vanes and those got sucked into the low end pump and that shelled that pump. They replaced the turbo and low end pump and casing.

I have had cold starting issues ever since and they have had it in at least 3 differnent times for that and an oil leak that I never had until the turbo blew. They have had it overnight and checked for oil pressure drop and it held pressure fine. the high end pump is supposedly OK and they made it sound as if there was nothing they could do until something else showed up. they di 2 new reflashes including the last one.

The manager thinks that this PCM has been acting up for that whole time but it didn't show enough to be found until now.....He feels the truck will start and run better once that is replaced.....hope he is right. again I really trusted the guy before this truck but I don't know if he has a bad tech or what. Or maybe it has been this PCM and it will get better.....Half full or half empty???

either way it isn't runninig right now.....

 

I agree, Matt, something doesnt sound right on this one!

 

Well,

the replacement PCM is on backorder. Ford supposedly agreed and OK'd the dealership to replace the PCM so they went to order one and it's on backorder.

They did say that this bad PCM will give the glow plug control module code and that the 2 EGR codes coincide with that. He feels that replacing the PCM will clear the problem......

Question. Is the PCM the main computer for the motor or are there seperate ones for seperate parts. Say there is one PCM for the glow plugs. Another one for the fuel delivery system, etc. I am just curious.

I appreciate you guys help. I am not real sure on all this stuff and if Ford is telling them this is what to do hopefully it is right. But I am real leary right now and any other opinions from guys who work on these help.

 

I don't know about this one... I am always doubtful when a pinpoint test directs PCM replacement, especially on a diesel (be it a 6.0 or 7.3). The backorder is normally the result of one of the following 2 reasons... excessive demand and the stock has been depleted, or in your case I imagine, little to no demand and there is no real reason to have any available. Just a question, but does it appear to you that this dealer does a fair bit of diesel work?

 

It's not a large dealership but it is in a city of 100000 with lots of farmers buying trucks. There is only one diesel tech there so I would say they don't work on a lot of diesels but he supposedly is certitfied....

I will hopefully get the truck back and if I feel anything isn't right I will try another one in the area......

 

While I tend to agree with Matt, Vince, and Canada on this one, anything is possible. Sometimes even the best of troublshooters have to throw parts at it to fix it. Vince, Matt, Canada.....is there anything that could zap or spike voltage in the pcm given the repairs performed? Mechanical repairs then causing an electrical problem just don't add up, but sometimes things are just coincidental. Please keep us updated on what happens next. Good luck, hope they get it figured this go-around.

 

There are 4 main network control modules controlling the powertrain- the Powertrain Control Module, the Transmission Control Module (in the same box and using the same processor as the PCM), the FICM (Fuel Injection Control Module, which interprets desired fuel commanded by the PCM and controls the fuel injector spools) and the Glow Plug Control Module.

The Glow Plug Control Module is the simplest of the 4 being not much more than a solid-state relay (transistor) box, but IMO is the most prone to failure. FICM failures are fairly rare with the exceptions of very early 03's and PCM failures even rarer. Alot of techs like to point to PCM failure as a parts swap because there are alot of issues that could correspond with it, but very few that actually do.

As Ryan suggested, anything is possible and I most certainly wouldn't step out and say that it most certainly is NOT the problem, but I do see it as being fairly unlikely. If the processor is still functioning well enough to run module diagnosis and pull codes, I just don't see it being the PCM. When the PCM does fail, the processor will normally fail totally and you will get no network transfer whatsoever- meaning that you can't retrieve DTC's, view PID's and network data nor reflash.

 

If you do try another dealer, let me suggest that you scope the place out first, and make sure that they are an actual diesel dealership, not just a dealership with a diesel technician. Trust me when I say that you have to be exposed to these engines on a regular basis to keep on top of things, not just once in a while.

 

I would come closer to believing a wiring chafe or a connector not seating properly.

 

Thanks all. I will keep you posted as to what happens next. Supposed to check after lunch today and see what's up with the back order situation.