Thanks Larry.

 

This is getting very frustrating. So since our last episode, we have had the one bad glow plug replaced and that resulted in the three codes reported above. So we decided to take it to a shop and they have tried everything, even replaced the GP Relay and now they say the computer is not talking to the glow plug or the relay. They are suggesting a new computer $500-800! Any ideas?

 

They don't know what they are doing and are guessing at your expense, get it back from them before they spend all your money. Why did they replace the relay? Did you check the 42 pin connector like Larry suggested?

 

As a matter of fact we asked them if they checked the connector et al and they said yes, they had spent 6 hours trying to figure out what was wrong. They did say that the old glow plug relay was good and the new one was not needed. The reason they replaced the old one was because, when they tested the old one, one of the sides was showing a weak signal (my words not theirs) so they replaced it. But then when they tested the new one it had the same weakness. We are headed to the mechanic later this afternoon to pick up the Ex. So what now? We are not experts nor experienced mechanics. So where do we take it now if we don't feel competent to dive into this deeper than we already have?

 

Hold on here!!!! These codes should not even show up if the PCM is correct for this rig. And this engine obviously has never had a glow plug monitor. This PCM is trying to talk to a module that is not there.

One of two things has happened here: either the engine with it's GPCM was swapped without changing the PCM, or the PCM was changed during the rebuild process after the accident.

Since this may have been a truck for sale as a new vehicle outside the state of California originally, it would not have a GPCM. I believe that the original engine would not have been changed after the wreck. The roll-over fuel shutoff would kill the engine, preventing any engine damage.

So following that logic, it is likely that the PCM in it's location was damaged in the roll-over. The re-builder ordered up a PCM and installed it, ignoring the immediate problem of a check engine light. The engine ran, it is Idaho, who cares about that light?

The fix here is to find a shop that knows 7.3 engines and ask them to obtain a PCM correct for this vehicle (a non-California vehicle) and install it. No more GPCM related codes. Problem solved.

After too many days of delay, who lives near Anaheim and can recommend a 7.3 shop that can help out these folks. C'mon guys!

Larry

 

Wow, your analysis is spot on Larry. And makes complete sense. The mechanic said he was going to try to find a PCM using my VIN which makes sense because the VIN is tied to the original configuration. Wouldn't that do the trick and shouldn't I just trust that he knows what he's doing? This is a well respected Ford certified diesel shop in Orange. My fear is that I've already offended by telling him I was going to come pick up the Ex.

 

I think you should call him and talk. He is used to dealing with folks that don't know about these vehicles and the 7.3. Just apologize, (tell him you want to save both your business relationship with him and also this very valuable vehicle).
Be honest that you did not have a complete understanding about the problem, but wanted to, before moving forward with putting more $ in the truck. It is not unheard of to have mechanics who do not know what they are doing. Obviously your guy knows what he is doing.
Just apologize and everything will be ok. He likes new customers, even when they get frustrated with the process. Sometimes relationships (personal and business) go through times of insecurity.
Larry

 

The VIN will tell your mechanic whether the truck is a California vehicle.

Another thought--I suggest you insure this vehicle to protect you should it be stolen/damaged while being repaired, even if not currently registered in California. Will insurance companies not insure vehicles that don't have up to date registration?

 

Thank you Larry. My gut has told me PCM from the beginning even though I didn't know why. It is likely that the YAYHOO who "restored" the truck after buying it salvage didn't have a clue. And I have learned a lot from this forum that I will bet not many people know. But we have had the SES light issue since we got the truck in 2007 but you are right it didn't much matter in Idaho. Now we got California personalized plates and they just came in, so I have to get this thing smogged within the next 30 days or lose the plates! Hubby is going to call the mechanic and grovel for me. I am so embarrassed!

 

Here is what my hubby said about his conversation with the mechanic:
I spoke with Fernando.
He said that we were thinking along the same lines, and he insists that he checked the PCM part number against the VIN number, and the replacement part he was looking for is the correct one.

He checked the harness. They tested every pin, end to end. They spent several hours doing so, just to be sure before moving on to suspect the PCM.

Fernando told me that even if we decided to come pick up the truck, he wouldn't charge us for the diagnostic work. That was his choice to do the extra work.

I told him that we should go ahead and order the replacement PCM (from a third party, not the dealer). He thinks he has a couple sources, and might have it in stock. He will call us back when he has an update ...

I think this mechanic has far better skills than I gave him credit for. He actually even offered to take it down to another shop close to him who does smogging and have it done for us once we get this thing dialed in.

 

Larry, not sure if you read from the beginning of the thread or not, but there was never a California prepped Excursion like for the F-series trucks. All of the 7.3L PSD Excursion's came from the factory with GPCM's.

If this Excursion came with a GPR from the factory, it would be the first one ever seen. It would be a Unicorn.

Stewart

 

Stewart, that is not what I read. There were several posts in early August that said there may have been some very early Exs that did come off the line with a GPR, like mine. I'm not sure whether it was Pikachu or you. I think it was you who said this is the earliest Ex he has ever seen on this forum. So this Ex could easily have been manufactured with a GPR not a GPCM.

 

The bottom line here is to get the truck operational in a way that enables it to be smog tested. Eliminating the SES light without installing a new harness and GPCM may be the most practical and least labor intensive solution.

I think the mechanic has shown some restraint and obviously wants to help his customer.

 

I'd be very curious to see the VIN and PCM code, see if they match up.

And if Fernando has a smog tech buddy who can make the whole problem go away, that's a very tempting offer.

 

I believe that was me, wondering aloud, because your rig is confusing. Yours would be the first known 7.3L PSD that came from the factory with a GPR instead of a GPCM.

Yup, it was me. I'm not sure the term "easily" can be used though when everything we've known up to this point is there were no GPR's put in Excursions. Possible, sure, ya never know with these auto companies.

I agree, but at the same time I'd like to document this as much as possible with build dates and matching numbers etc just in case this rig did indeed come from the factory with a GPR.

Stewart