Hello, and good day to all. I would like to present a challange to be able to read/write code to any vehicles PCM via laptop. This will enable us to tune the cars computer to suite driving needs according to mechanical modifications made to such. I do not know what hardware/software we will need. I have tried searching for an interface to hook up a laptop to the pcm but all I keep finding is some kind of tuners. I have a 1999 F-350 7.3L Powerstroke Diesel that I would like to reprogram to suite my needs. Ok well thanks for listening and if anyone has any info/ideas or can point me in the right direction please don't hesitate.
I don't think you're likely to find this since from my experience, the aftermarket uses plug in EPROM or Flash chips that replace the OEM chip rather than reprogramming it. That at least implies that the OEM device is a PROM rather than Flash.
I recently had to have my wife's 1999 F250 7.3L PSD (sounds familiar ) towed to the dealer because the PCM was dead (it was cheaper to have the dealer diagnose it than for me to buy a rebuilt PCM). It turned out to be a bad aftermarket chip. The dealer replaced it with the OEM one and it was fine after that.
What do you want to change on the computer that you can't find on the aftermarket?
You seem to have a valid point Engineer1138 nobody seems to be just reflashing the pcm. I have currently discovered Moates Quarterhorse which plugs into the pcm and uses software via laptop to data log/change pcm behavior in real-time. Unfortunately they are closed this weekend I am going to give them another call next week. I will most likely go this route, at least at first until I understand more of what is going on then I will try to make my own interface possibly using atmel avr atmega16 chip or equivalent. That way it puts me back into my comfort zone (knowing exactly what makes everything work and being able to make changes or replace $4 dollar parts instead of $250 dollar parts. I may even eventually build my own PCM from scratch. Once you are in the driver seat (Total pcm control) if you can think of it you can build it.
kheston wrote:If you find any good posts about a DIY ODBII interface, please post. I poked around for one some time ago and didn't have any luck.
The protocol specs are hard to come by unless you're willing to fork over the dough and purchase the standards manual. If your car happens to use the ISO9141 you'll have better luck making something cheap. I don't like the price much but this chip http://elmelectronics.com/connect.html#ELM327 makes building and OBDII project a snap. It's very easy to interface with a computer or microcontroller. There are several good (and free) Windows and Linux programs that work with the various ELM interpreters. I'm in the process of building an OBDII data logger using the ELM323 chips and a PIC16F627A if you want a little guidance in that area. Let me know if you're interested and I'll dig up the links for the Windows programs I mentioned.
Hello, and good day to all. I would like to present a challange to be able to read/write code to any vehicles PCM via laptop. This will enable us to tune the cars computer to suite driving needs according to mechanical modifications made to such. I do not know what hardware/software we will need. I have tried searching for an interface to hook up a laptop to the pcm but all I keep finding is some kind of tuners. I have a 1999 F-350 7.3L Powerstroke Diesel that I would like to reprogram to suite my needs. Ok well thanks for listening and if anyone has any info/ideas 
or can point me in the right direction 
please don't hesitate. 
) towed to the dealer because the PCM was dead (it was cheaper to have the dealer diagnose it than for me to buy a rebuilt PCM). It turned out to be a bad aftermarket chip. The dealer replaced it with the OEM one and it was fine after that.