How do you reset service 4 wheel drive indicator on a 2002 Chevy trailblazer?

To reset the service 4-wheel drive indicator on a 2002 Chevy Trailblazer, first, turn the ignition key to the "On" position without starting the engine. Then, press and hold the "4WD" button for about five seconds until the indicator light blinks and then turns off. If the light persists, it may indicate a deeper issue, and you should consider consulting the vehicle's manual or a professional mechanic for further diagnosis.