Cadillac 2010 DTS Owner's Manual page 213

The speedometer shows the speed in both miles
per hour (mph) and kilometers per hour (km/h).
See MPH (km) under DIC Operation and Displays on
page 4 61 for more information.
The odometer mileage can be checked without the
vehicle running. The vehicle's odometer works together
with the driver information center. Trip A and Trip B
can be set on the odometer. See Trip Fuel under
DIC Operation and Displays on page 4 61 for more
information.
If the vehicle ever needs a new odometer installed, the
new one is set to the correct mileage total of the old
odometer.
This gauge indicates
the engine speed in
revolutions per
minute (rpm).
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