Reading error codes 1994 Tran am

JUSTSTOPIT

MEMBER
1994 PONTIAC FIREBIRD

Hi,
I have a 1994 firebird trans am 5.7, 12 pin connection, that I need to get the trouble codes on. I have tried the paper clip method & a standard non digital reader on this car & nothing happens, codes read fine on our 95 truck. I found some digital code readers that say that work on some obd 1's but they are very pricey and sales are usually final. How can I be sure the one I buy will work on this car? I have a hypertech power programmer that works fine (doesnt have the code reader function) & my check engine lights work, so I know my connection is good. Is there any other way to get these codes? Any help would be greatly appreciated!

1 Reply

EDI3000

MEMBER
34 POSTS

If the "check engine" lamp lights for a bulb check but stays out, and does not flash any codes, check the continuity of pins A & B in the ALDL. Connect the voltmeter + to ALDL pin A. Connect the - lead to battery neg. With the ignition on the voltage drop should be less than 0.1 volt. Then check to see if you get 5 volts on pin B. Try grouding pin B with the engine running and see if the "cel" flashes. Try that, in a few cases, communication errors can be caused by PCM failure. If all fails, have somebody connect a scanner, then you can see for sure.