I have a 94z28 that was an automatic.I have a new pcm and engine harness that i installed when i did my conversion from an automatic to the six speed. When i installed the harness i had issues with the fuel injectors not firing and later found that the harness had only 1 power wire feeding the injectors. I spliced the power over to the second injector bank and the car started. I have had some issues with the car ever since the conversion and I am about ready to give up and by something else. when I got the car to run i used the power programmer on it and it worked fine. when i try to use the datamaster reader on it i get no pcm detected--and this does work on other cars. I was wondering if i have the wrong harness or pcm--i was told they both came from a 94 z28 with a six speed. I do not know if there is a way to find out what the pcm is from--number of some kind???? I also would like to know if mabye i have a harness from some other year.
Any ideas would be great.....if some one local could help that would be even better--I live in the frisco/plano area. thanks to all who help.

 

what is the service # on the PCM.. last 4 digits should be 8051 i believe.

what procedure did you use to try and read the PCM?

you didnt even need a new PCM... you coulda flashed your old one with a 6 spd program.

 

i will look on the pcm for the numbers -- i have a laptop with the datamaster software on it and it will read everyone elses car but mine. did not know about the reprogram option when i did the change--- also do not have any connections locally that can help with pcm program/diagnosis. i am going totry to see if the harness has missing or rerouted wires like the injectors.
thanks

 

i found a number on the side of the pcm it looks like a sticker with a barcode and some number above it --- i did not know if some one could tell me what these numbers mean or if i have the wrong numbers. the number is 16202061 and then there are some letters --BMKZ
thanks for any help you all can give

 

Did you change the entire wire harness on the engine management system? You could have just left in your orginal harness and then use the t-56 swappers guide and reflash your ecm. I guess the only other thing is to double check your old harness to the replacement one, make sure all groungs are connected and the put in the A-4 ecm that has been reflashed to that of a m-6 vin.

 

i did the swap with some one that needed the auto stuff--i do not have the old parts -- i pulled the pcm and there are more numbers under the cover and these match the 8051 mentioned earlier. this still does not solve the issue with not having the ability to connect and talk to the pcm....i will have to trace all wires one by one and see what is screwed up. if datamaster cant communicate with the pcm i dont see how any other program will communicate to even be able to reprogram with all the changes i have made to the car.

 

the pcm saga continues--i checked the wires to the pcm and they are correct--i used the shop manual to run the checks for voltage and shorts---it all checks out ---(unplugged the modules and checked for voltage--then replugged them in) ---test shows that the modules are working and the pcm is just not communicating---still cant read or talk to the pcm with the datamaster on my laptop
if anyone has any other ideas or ways to read the pcm i totally lost at this point