1994 Corvette Owner in Vancouver, WA

Hello! I'm here as I bought a '94 Corvette recently and I intend to do some PCM tuning and trouble shooting. My car is a 6-speed so I intend to disable the skip-shift and read the DTCs which my CCM won't show me for some reason. I know I have a DTC set as my cooling fans run continuously and the dash is showing "SYS". I bought the factory service manuals off EBay which already helped me with the climate control. I have a 16-pin male ALDL connector and some female DB9 connectors on the way to build an adapter; I want to use the FTDI USB to DB9 serial cable I already own.

I'm a telecommunications electronics tech so the hardware side of things doesn't bother me, but code puts me to sleep. I greatly appreciate what coders do for us so thank you.

welcome, lots of LT1s over here, get the free stuff in my signature it'll help a lot

skip shift will be easy to get rid of, just drop the max tps and/or coolant temp to an unreasonable range (and disable the error code for the solenoid if you plan to remove it)

eehack will read all of your DTCs, and you can also query it for the bizarre and mostly useless vette-only pre-obd-ii diagnostic errors that no other scan tools read (if your ECM revision supports them) but if you use eehack to flash your car with patches included, it'll overwrite that error set in favor of a more optimal logging configuration.

Thanks Steveo!

I've downloaded EEHack and TunerProRT, but haven't yet installed them. I have a fair bit of reading to do while I wait for my cable parts to arrive. Can you say more about the reflash patches and logging or point me to a pertinent document? I've not tackled electronic tuning before, but have played extensively with carbureted engines which has given me a fair understanding of the effects of timing and fueling. This is my first Corvette and as the most tech-laden Chevy it certainly does have its weirdness.

most of eehack's help files are stored in 'tooltips' so you're forced to explore the program, if you hover your mouse over a control it'll explain quite a bit about it sometimes. for example go into the flash tool and hover your mouse over 'insert patches', and it'll explain how those work.

there's also a nice info button beside that patch checkbox that tells you what the patch version contains exactly i suggest you click it, especially since you have a corvette, one other thing it does is replace 'oil temperature' in the datastream with 'afr target', since afr target is generally much more useful.

then there's this for more details about speed logging

http://fbodytech.com/eehack-2/eehack...w_does_it_work

you'll love electronic tuning just make sure you put tunerpro into 'category' view mode with the EEx xdf, and everything will be pretty easy to find in there.

download your bin in advance and start playing with it: http://fbodytech.com/bin/EE_16200901.bin

eehack has a lot of stuff in it, but a good start is to connect it to your car, drive around for a while in varied conditions, and when you get home, click 'analyze' and then 'run analysis' to get a good idea where your AFR and any knock is. i tried to make common datalogging to fuel/spark analysis workflow as fast and easy as possible.

Sounds good! I'll start poking around in the software while my ALDL connector is on the way. If I get impatient I'll just insert bare pins and see if she talks.

The adapter cable I made failed to work so I got my hands on the SparkFun FTDI breakout and now I'm talking with EEHack. It's odd. The only stored code in the main window was for low coolant temp, but even after clearing it I can see Fan1 run constantly. I can command it off and hear it spin down, but it comes right back on when put back into auto. I logged a warmup cycle, but I won't bore you with that unless you want. I'll look deeper into trouble codes tomorrow, but for now I'm happy to have comms working.