GMT800 (1999–2002) Engine Hours

The early GMT800 trucks (1999–2002) don’t officially have an engine hour readout like the later 03+ trucks… but there’s a built-in workaround using the gauge cluster.

If you didn’t know this, it’s already in your truck, accessible via the guage cluster (without using a scan tool).

How to access it:

  • Key OFF (engine off or running)

  • Press and release the trip/reset button on the cluster to show the odometer

  • Press and hold the trip/reset for 3 seconds to display engine hours

  • After 3 seconds, there’s a hidden sequence that will show total engine hours

It’s not documented clearly, and most guys miss it completely (we hope this post will change that)

WATCH BELOW:

Engine hours should always be taken into consideration when purchasing a vehicle.

  1. Way more accurate than mileage for wear
  2. Helps when buying a used truck
  3. Shows true idle time (huge for work trucks, plow trucks, etc.)

If you take the mileage/hours you will get the average speed driven. From the video: 201,777 KM and 4,874.9 engine hours. This equates to an average speed of 41.39 KM/h or 25 mph.