My setup:
I have a 95 LT1 auto bolt on with custom tune. The tune was done by Bryan at pcmforless about 6 to 8 years ago. I communicate via the command prompt in Win XP. The software I use is from Bryan and is just for reading / backing up / and flashing. I use a pre-made cable from AKM cables. I now live in Ohio and have to pass smog tests every two years.

I drove the car to warm it up about 4 miles. I pulled over to the side of the road and turned on the laptop. I opened the command prompt, ran the software, establish communication, selected to back up first ( its been a few years I just wanted to make sure it was all still working), and completed without issue.

Now I go to flash the factory tune back into the car. I run the software, select to load, establish communication, pick the original tune, watch the flash load ( 0 to 100% ), fans shut off, pcm restarts, completed successful note pops up in the software, try to start the car. It wont start and only cranks.

I figure ok if it wont run on the original tune I will go back to Bryan's tune. Again run the software, establish comms, pick the custom tune, watch the load, fans shut off, restarting pcm message comes up THEN IT TURNS TO CRAP ON ME!! Instead of a successful message the software tells me there is an error. I tried to establish comms again and can no longer talk to the PCM and the car only cranks.

Question: Did I somehow fry my PCM? I have done this exact procedure before without any problems. Is there any way to reset my PCM or have it checked by someone without giving the dealer $500 bucks for a replacement? If I have to replace it what do I need? Does it have to be a 95 PCM with an auto?

Thanks in advance for any help.

Dave

 

I should have also mentioned my battery voltage was getting low. I have 4 guage wires hooked up for ground and between the alternator and the battery. It usually runs above 14 volts on the dash when running. While doing these flash games with the key in accessory it dropped to 9 ish volts.

Dave

 

Sounds like the PCM bias code is messed up,takes special software to get it repaired cost about $50.00 and done by some of the tuners. Search on "flash PCM repair". Or a junk yard may have one for in the $50-$100 range. You can use a '94 or '95 the PCM from any F-Body or many B-Body cars the part number is 16188051 the same PCM for A4 or M6 but the software code (.bin file) is different between the A4 and the M6 and also important the '94 and '95 A4 software is different because the '95 added the Pulse Width Modulation solenoid (PWM) to the Torque converter setup and you need '95 code to support it. So you need a 16188051 and then load it with good '95 A4 .bin file. Not sure if I would trust the .bin you have, although it certainly looks like the 9V could not help it any, I believe the PCM will crap out at 8V, but that's not written anywhere. Brian may be able to assist, but since it's been years I wouldn't expect it will be free.

 

Forgot to add.. if you have an ALDL cable, you can download TunerCat "Tuner" program for free for 30 days and download the TunerCat "$EE" definition file for $20.00. You will then have the latest 15 year old code available to read, edit and load your PCM. You can get a good stock '95 A4 .bin file from many sites and then use it to build your modified tune back up. Probably not much help on that command line program you are using will be around any more, I never used it, but it was around for a while and is still used, but not much on the forums about it.

 

When I started this whole process the very first thing I did was back up the factory tune in the PCM. I have my original .bin file and don't see any reason it would be bad but you never know. Used PCM's on ebay seem to be in the $100 to $150 range so if I can get mine repaired for $50 its a better deal. Does the .bin load everything I need in the PCM?? For example if I can get a 94/95 M6 PCM will my A4 .bin load it correctly OR are the some things the .bin doesn't address requiring me to get another A4 PCM?

Dave

 

The program Bryan gave me seemed to work fine. Are you saying it could also be part of the problem and thats why I need to use tunercat? I have the modded .bin and really didn't want to get into editing.

The command prompt reference was to start / run / cmd to open the command prompt in windows. It seemed to work fine on the back up. Maybe running that in Win XP was the whole problem but I am pretty sure I used xp last time with no problems.

Dave

 

First .. loading a good .bin is all you need to do after you install another PCM the .bin will install base code plus your tune.. .Second if you are happy with the current load command line program there is no problem with it that I know of.

 

thanks for the help. i email'd bryan and he thought the PCM is bad based on the info. he recommended i run to the nearest bone yard and pick up a cheap one. now i just have to find it at a reasonable price.

dave