GM Service Manual Online
For 1990-2009 cars only

To access the engine hourmeter gage press the trip odometer button three times.

The instrument panel cluster displays the accumulated engine run time hours using the reconfigurable odometer display. The engine run time hours displays only when the ignition is in the LOCK/OFF or ACC/ACCESSORY position and the trip reset switch is pressed for about four seconds.

When the ignition is in the LOCK/OFF or ACC/ACCESSORY position, the instrument panel cluster displays the engine accumulated hours for up to 30 seconds. The value of the accumulated hours does not change when the battery is disconnected.

The hourmeter resets to 0.0 when 10,000 hours are accumulated. The instrument panel cluster begins to reaccumulate the engine run time hours from 0.0 hours.