1998 Buick Lesabre Check Engine Light

Did you check for voltage at pin 16 data link connector? Pins 4 and 5 are grounds. One way to see if computer is awake, key on, check for ref voltage at any sensor that uses a ref voltage, if nothing, Have to check voltage and ground circuits for computer before saying anything about the computer itself.

If you want to check the circuit for the check engine lamp, we can do that, also. I haven't looked at wiring for that, usually the pcm grounds that circuit in order to turn on the lamp.

Anybody with other ideas, jump in.