Hello,

Ipicked up a 94 camaro with a lt1 motor that had a blown head gasket. It was partialy disasembled when I got it. After changing the head gasket the car runs but with a bad miss. So I hook it the car up to a scanner and I can't connect, pull codes, view data, nothing. So I try conecting the two terminals on the ALDL, check engine light comes on and stay on and the cooling fans kick on. No codes are flashed, not even the first one its always supposed to flash. Im kind of thinking the computer is shot but are there any other things I should look into before I replace it or websites with good troubleshooting info. I already checked the wiring to the ALDL conector. Any help would be appricated.

 

Make sure you are using an OBDI scanner. The connector looks like OBDII but it is OBDI. You need a special adapter cable.

 

I think I have the same problem. Hopefully the computer isn't brain dead. I am going to start disconecting stuff to see if I have a ground or short somewhere.

 

i have a problem my servise engin light is flashing but iit will not put out a coad. but it flashes weard if you can help that would be grate.

 

I have a stock 94 PCM to get rid of if that turns out to be the problem

 

Update on my 94 Z28. Running great now after replacing an $11 coolant temp sensor. It did need new plugs, wires, optispark and water pump too at 90,000 miles. Never was able to get a code out of it . I still can't figure out how this was causing my engine to die, should have just engaged the limp home mode. Think I might keep it for another 90K miles now, asI was considering getting rid of it when it was being a pain.

 

is that common i have a 93 z28 and i am having the same problem but i am flashing code 12 over and over. and i cant pull any codes i tryed like 4 different scanners. i think it is the pcm

 

Code 12 is not a trouble code, it just indicates the start and end of a series of trouble codes. This code will flash if the A & B pins of the diagnostic connector are shorted together or if the B pin is grounded, and the ignition key is ON.
12.12.12__code__code__code__12.12.12 . Code 12 by itself is not a trouble.
Look for a short between pin B (WHT/BLK stripe wire) & pin A (BLK/WHT stripe wire) and a short between pinB & GND. Pin A is always grounded.
Diagnostic connector pin layout:
F E D C B A
G H J K L M

 

ya i know that i grought it in and he checked every think all the grounds all the wires there are no shorts so he says that there is a short in the computer. and he also says that they go out offten. idkthis guy wouldent lie to me. idk i kinda hope it is the computer becouse the dealers said that there are three in the usa and i am getting one of them. and they are on back order that many of them are broken. if not i will just send it back.