How do you reset check engine light on 1990 Suburban?

To reset the check engine light on a 1990 Chevrolet Suburban, you can disconnect the vehicle's battery for about 15 minutes. This will clear the engine control module's (ECM) memory, including any stored trouble codes that triggered the light. After reconnecting the battery, start the vehicle to see if the light remains off. If the light comes back on, it may indicate that there is an underlying issue that needs to be addressed.