GMC 1997 Safari Owner's Manual page 133

Speedometer and Odometer
Your speedometer lets you see your speed in both miles
per hour (mph) and kilometers per hour (kmh). Your
odometer shows how far your vehicle has been driven,
in either miles (used in the United States) or kilometers
(used
in
Canada).
Your odometer is tamper resistant. The digital odometer
will read 999,999 if someone tries to turn it back.
You may wonder what happens if your vehicle needs a
new odometer installed. If the new one can be set
to the
mileage total of the old odometer, then it must be. But if
it can't, then it's set at zero, and a label must be put on
the driver's door to show the old mileage reading when
the new odometer was installed.
Trip Odometer
The trip odometer can tell you how rar your vehicle has
been driven since you last set the trip odometer to zero.
The trip odometer will appear in place of your regular
odometer when you press the
TRIP
button.
To reset
the trip odometer, press and hold the TRIP
button. To change back to the regular odometer, press
the TRIP button again.