Check engine light is on without an error code in a Mitsubishi Colt

Check if the OBD-II scanner you are using is compatible with your Mitsubishi Colt. Sometimes, certain scanners may not read all codes. If the scanner is compatible, try disconnecting the battery for a few minutes to reset the ECU, then see if the light returns. If it does, it might be worth visiting a professional mechanic to ensure there are no underlying issues. Let me know how it goes or if you have any further questions!