E 450 V10-6.8L (2008)
Compass: Description and Operation
ELECTRONIC COMPASS
A compass and ambient air temperature display are contained in the overhead console. The compass sensor is located inside the compass display module
(which is part of the overhead console). The ambient air temperature sensor is attached to the radiator frame located behind the grille.
Compass Accuracy
Luggage racks and magnetic mounted devices like antennas should not be located on the front third of the vehicle roof. Placing these devices near the
compass causes inaccurate directional readings. If these devices must be used, accuracy of the compass may be improved by calibrating the compass
while the devices are installed on the vehicle.
Driving near power lines, or driving in the area of large iron or steel structures can temporarily change the compass heading. If the compass remains
inaccurate after driving near such objects, demagnetize the vehicle.
Most geographic areas (zones) have a magnetic north compass point that varies slightly from the northerly direction on maps. This variation is 4
degrees between the adjacent zones and becomes noticeable as the vehicle crosses multiple zones. A correct zone setting eliminates the error.
Ambient Air Temperature
The ambient air temperature reading can be affected by engine heat when the vehicle is idling or has been off for less than 2 hours. The ambient air
temperature display limits the increase of the displayed air temperature to one degree per minute at very low speeds or immediately after the key is
turned to the ON position. After 2 minutes at a sustained speed of at least 53 km/h (33 mph), the effects of engine heat are minimal and the ambient
air temperature display will show the current ambient air temperature reading. Temperature decreases are always updated immediately.
If the ambient air temperature falls below 3.3°C (38°F), the ambient air temperature display alternates at a 2-second rate from "ICE" to the ambient
air temperature for one minute after starting the vehicle. After one minute has elapsed, the ambient air temperature display will show only the
temperature reading.
