Major PCM issue
 

Long story short, when I updated my SCT tuner's firmware, it destroyed my stock tune. SCT "manufactured" a stock tune for me without the PATS info. Car ran fine, but they said I had to take it to Ford for fix the PATS.

So, off to Ford. From the outset, the maintenance folks said, we can do the PATS for about $100, but if we have to get the Ford engineers to send us a file created from the VIN/build sheet, it will be $250. The dealer also started saying how tuners can fry the PCM. They said that alot.

The next day Ford said that they uploaded the tune into the PCM, but the PATS was not yet working. Again, they stressed the PCM may be fried.

Today I call and I'm told the PCM has been fried.

Here's my problem - I don't believe them. I'm not a computer geek, but I understand corrupted files DON'T fry electronics, electricity and heat do that. So I'm about to get a quote for over $1000 to fix it.

I know some of you guys are Ford techs, so give me the straight facts. Am I wrong or does it seem like I'm being taken for a ride?

A tuner changes some of the eprom code in PCM. If the code in the eprom becomes sufficiently corrupted then the eprom won't even have some of the basic codes to follow the instructions its being give, essentially 'frying' the PCM.

They dont' mean 'frying' it as in burning it up electrically. They mean bricking it as in it is now just as useful as a brick. Just like if you try to update the firmware on your phone with an incompatible version. You'll brick your phone (fry it).

And yes, it is plausible this happened to your PCM.

PATS uses both the instrument cluster microprocessor and the PCM, which are "married" by a security ID programmed into both at the factory. It can be reprogrammed using the Ford IDS (Integrated Diagnostic System), and does require that they contact Ford to get a new code pair.

As to the PCM being "fried", while it is not likely that the SCT tuner could do that it is possible. To program the EEPROM (Electrically Erasable Programmable ROM) an 18V programming signal is applied to pin 13 of the OBD2 port, in turn connected to pin 13 on the PCM. This voltage is what is needed to reload the memory cells in the EEPROM.

If it were too high (more than 19.5V or so) the EEPROM could be permanently damaged, if too low (less than 17V) the contents of the memory cell would not be properly programmed, but likely not damaged. However this can cause most end-user flash tools to no longer flash that PCM, as a safety precaution.

FWIW, and not really related to your problem, here is what you need to "bench flash" a EECV PCM.

I have never "force flashed" a PCM, however I just now called Pat Stajdel at Delta Force Tuning and told him of your situation. He said that if you send them the PCM they can do two things, first determine whether it is good or not and if it is good force flash a stock tune and send it back to you.

There would be a nominal fee + shipping, however they will not BS you and will be able to figure out what is up. If you like contact them at tech@deltaforcetuning.com, or 407.321.5725. Mention my name and that I had spoken with Pat, they will let you know the cost, etc.

I could force flash it with the tools I have, however they have the tools to fully diagnose and test the PCM.

This will not address the PATS issue but it will get you running again for a lot less than a grand--if the PCM is good.

Cliffy, I have no idea what you said, but it sound right. Lol

1st follow up:

I spoke with a service tech from another dealer yesterday. He stated that it is extremely rare that tuners utilizing the ODBII port cause the PCM to lock up. I relayed to him what I was told and he didn't think it added up. If the PCM does not accept the tune, he said you'd know it immediately. The dealer that has it now said it took them a day to figure out the tune didn't take. I'm going to re-install the "emergency" tune SCT made for me that got the car running today, if they have not trashed the PCM at the dealer. Next week, I'll try the other dealer. More to follow.

Sounds like a plan, if that doesn't work out we are ready to help...

Dealer B is correct about knowing "right off the bat" that the flash programming failed--all flash tools verify the tune data after flashing, and would let the user know if it was not what it thought it programmed...

Cliff -

This whole disaster has given me an idea that you may find of interest.

What about creating a data bank of stock tunes? For example, I buy an SCT tuner. I upload my tune and the stock one is now in the device. I copy the stocker from the device to my HD and then upload it to a company that stores it for me as a back up. Maybe a one-time fee of $5 for that service.

Something like this would have saved me a lot of grief. Maybe there's money to be made here, maybe not. After my experience, I'd pay.

The thing is that at very, very best there would be maybe 200 people interested in such a service--so at $5 a pop I'd collect a whopping $1000 to be responsible for this data from now until the end of time--the math doesn't work.

It doesn't seem that way from reading the forums, however I'd be surprised if there are more then 25k Mustang enthusiasts out there that have any tuning tool--good idea for a poll, think I'll do it...

Maybe, maybe not. Again, simply an idea. Expand the concept to bank all tunes for $5. The files are typically less than 250kb.

Let me see if I can adequately relate what I was told by the dealer. I needed a new PCM because there was a communications error with the HEC module. Or something like that. So, is the PCM the box behind the passenger kick panel, because it looks the same as before. I paid $1200 to get the car back on the road, so I'd like to know.

To top things off, on the way home, I notice my hood lifting - they did not close it completely. I pulled off, lifted the hood, and immediately saw my belt routed incorrectly and rubbing the passenger side head at two points. When I called the dealer to send me a 3/8" breaker bar, the tech claimed he'd not touched anything under the hood. I guess the shop gremlins did it. One did come out with the tool and I fixed the routing in 5 seconds, but for the love of God, they are a dealership and screwed something that simple up. Needless to say, the other dealer in town will get my business if needed.

The PCM is the "box behind the passenger kick panel", whether they did anything worth $1200 is another whole story--depends on the dealer, some are there to help and some are there to screw you over..

A raw EECV tune file is 229,376 bytes, they can grow and shrink depending on a particular vendor's encryption scheme. However there is nothing magical about them, it's just a plain ol' binary file.

Burn it to a couple of CDs, or save it as part of your normal backup routines.