To get the diagnostic trouble codes (DTCs), a mechanic needs to use a scan tool specifically designed for OBDI systems from that era. These tools would read the codes stored in the PCM (Powertrain Control Module). The codes are a series of numbers, not readily available via the check engine light itself.
Therefore, there's no list of codes you can look up based solely on the light being on. You must use a scan tool or take the vehicle to a mechanic who has the proper equipment to retrieve and interpret the diagnostic trouble codes. The codes themselves will point to the specific problem(s) causing the CEL to illuminate.
