[sweetbmxrider]

To extract a trouble code from the computer for diagnostic purposes, the twelve pin data link connector (DLC) is used.
The DLC is located in the passenger compartment. Terminal B of the connector is the test terminal and terminal A is the ground used for diagnostic display.
If the test terminal is grounded with the ignition on and engine not running, the system will enter the diagnostic mode. In this mode, the computer will display a Code 12, three consecutive times, by flashing the "CHECK ENGINE" or "SERVICE ENGINE SOON" light. A Code 12 consists of one flash, a short pause, then two flashes in rapid succession. After Code 12 is displayed, any stored trouble codes will be displayed by flashing the "CHECK ENGINE" or "SERVICE ENGINE SOON" light. All codes are displayed 3 times each then a code 12 will repeat. In the diagnostic mode, the computer will also energize all computer controlled relays and solenoids

If the test terminal is grounded with the engine running, the system will enter the field service mode. In this mode, the "CHECK ENGINE" or "SERVICE ENGINE SOON" light will indicate whether the system is in open or closed loop operation. If the system is in open loop operation, the light will flash approximately two and one-half times per second. Closed loop operation is indicated by the light flashing approximately once per second. A "Scan" tool can be used to enter the "Field Service Mode."

Connector D Terminal 30 on the pcm is for serial data communication. Ohm it out to the DLC. Maybe someone local has a known working 94 computer that you can swap in and check for communication after verifying communication in the donor vehicle.