There are two mileage readings that you can reset on your Chevrolet Trailblazer: the trip mileage and the gas mileage. Either mileage setting can be reset easily with GM's driver-information center, the controls for which are located on your steering wheel. But remember that the overall mileage that appears on the Blazer's odometer cannot be reset. This is illegal in most jurisdictions, as it can lead to odometer fraud, a criminal offense.
Resetting the Trip Mileage
Step 1
Sit inside your Trailblazer with the engine running. Locate the "Trip" button on your steering wheel. This button has a highway icon.
Step 2
Push the "Trip" button and look at your odometer. It will cycle through "Trip A" and "Trip B." Choose the trip mileage that you want to reset. You can reset both one at a time, if desired.
Step 3
Push and hold the stem on the odometer. This is located in the right corner of the cluster. Hold it down until the mileage resets to "0.0."
Resetting the Gas Mileage
Step 1
Sit inside your Trailblazer with the engine running. Push the "Fuel Info" button on the steering wheel. This button is represented by a gas pump icon.
Step 2
Continue pressing the "Fuel Info" button until "Average Fuel Economy" is shown in the odometer. This is your average gas mileage.
Step 3
Push the "Select" button and hold it down. This is the button with a "Check" on it, located on your steering wheel. After a few seconds, the gas mileage will reset. After a few minutes of driving, it will recalculate itself.