Bipolar

Im trying to find out if my 94 LT1 PCM is working or not. I have no spark. I put a new Opti on it today and a new coil and still no spark. I have checked all the fuses, so im down to the PCM and ICM. Can I have the PCM checked/tested?

Jditlfm

iTrader: (26)

First make sure you check the ignition fuse under the hood. I fried my icm by cranking the engine without the coil wire pluged into the opti, and i have also blown my ignition fuse by crossing wires that go to the icm. Pcm's rarely go bad unless you have jumped the system causing a voltage spike but i think you would know if you did this. I have also had were the o2 sensor wire burned on the headers and cause me not to have any spark. If it is none of those things i would be very surprised to end up being your pcm

moehorsepower

iTrader: (3)

If you have any tuning software LT1 Edit, HP, ect, If you can talk and read to the PCM then it is ok...

rbrcka

I am currently having a crappy running situation that I've been troubleshooting since I bought my car a few months ago. I have noticed that I get data errors when I try logging anything.

Today I tried TTS Datamaster for the first time and I was getting a constant rotation of the following: Data Collection Active -> Lost Com, Reconnecting to ALDL..., No PCM Sync, Recycling. This was on my custom mail tuned PCM. Then for grins I hooked up a spare PCM that's the same serial number, but has the vin/config for a 4.3L. Obviously the car ran like crap, but the data sync was not dropping for the entire time I had it running. The interesting thing is that I still can't "read" the config from either one with winflash, but does it sound like my tuned pcm might be bad?

rbrcka

The guy who programmed my pcm thinks it sounds like it could be bad. Any other other opinions before I shell out some more money to have him put my custom tune on the spare?

moehorsepower

iTrader: (3)

Again...If you have any tuning software LT1 Edit, HP, ect, If you can talk and read to the PCM then it is ok...

rbrcka

It's weird because with winflash I can read the vin number, but it always fails trying to "read" the config. I tried this with my laptop and even brought my desktop out to the garage because the TC support thought my laptop was the issue after reviewing the logs. I get the same problem with either computer and with two different PCM's. However, the PCM I have been using in the car gets sync errors when logging and the other doesn't. So I'm wondering if the "read" issue is different. I'm going to go ahead and have the spare PCM tuned since that one seems to keep sync during logging. Hopefully it makes a difference.

RUNINHOT

iTrader: (10)

Had my computer go out. It would perodically cut the injector pulses off for no reason. Later they would come back on. Drive the car for anywere between 15 minutes to 30 and it would cut them off again for no reason. Took me forever to find out it was the computer.

rbrcka

I thought I'd just follow-up with what I found on mine in case somebody else runs into the same trouble as I had. I cut the serial data wire at the pcm (blue pack pin 30) and pieced in a brand new section of wire to the diagnostic port "M" connector (bottom right on my 12 pin obd1) completely bypassing the stock wire. The very first attempt I was able to read the pcm config and I can now datalog without a constant stream of data errors that made it impossible for me to get any reliable data. Now I have a shot at getting this damn beast straightened out!