Dodge 2009 Ram Chassis Cab - Manual (Page 145)

Compass Variance is the difference between magnetic
North and geographic North. In some areas of the
country, the difference between magnetic and geographic
North is great enough to cause the compass to give false
readings. If this occurs, the compass variance must be set
according to the Compass Variance Map.
NOTE: The default for the compass variance is Zone 8.
To set the variance: Turn the ignition ON and set the
display to “Compass/Temperature.” Press and hold the
RESET button approximately five seconds. The last vari-
ance zone number will be displayed. Press the STEP
button to select the new variance zone and press the
RESET button to resume normal operation.
Outside Temperature
Because the ambient temperature sensor is located un-
derhood, engine temperature can influence the displayed
temperature. Therefore, temperature readings are slowly
updated when the vehicle speed is below 20 mph
(30 km/h) or during stop-and-go driving.
Compass Variance Map
UNDERSTANDING THE FEATURES OF YOUR VEHICLE 143
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