To properly address the check engine light, you need to:
1. Get the diagnostic trouble codes (DTCs): A 1993 Cadillac DeVille uses an OBD I system. You'll need a special OBD I scanner or a code reader compatible with that system to retrieve the DTCs. Auto parts stores often have these scanners available for rent or can scan your car for a small fee. Alternatively, you might be able to perform a "jump wire" method to read the codes, but this is less reliable and requires specific instructions for your car model. Searching for "1993 Cadillac DeVille OBD1 diagnostic" will provide more details on this method.
2. Interpret the codes: Once you have the codes, consult a repair manual (Haynes or Chilton are good options) or an online resource to understand what each code means. This will tell you the specific problem the car's computer has detected.
3. Repair the problem: Based on the DTCs, fix the underlying mechanical or electrical issue. This could involve anything from replacing a sensor to more extensive repairs.
4. Clear the codes (after repair): *After* successfully repairing the problem, you can clear the codes. On some OBD I systems, disconnecting the battery negative terminal for a period (e.g., 30 minutes) might clear the codes. However, with a scanner, you can typically clear them directly. Again, your scanner should have this option.
In short: Don't focus on resetting the light; focus on fixing the problem causing it. Ignoring the check engine light could lead to more serious and expensive problems down the road.
