F 150 4WD V8-5.4L Flex Fuel (2008)
C4-C6
Test D: The Compass Is Inaccurate
PINPOINT TEST D: THE COMPASS IS INACCURATE
Normal Operation
The compass module (without auto-dimming interior rear view mirror) or interior rear view mirror (with auto-dimming interior rear view mirror)
communicates vehicle direction to the instrument cluster (IC) to be displayed in the message center through circuits 702 (WH/BK) and 703 (WH/OG).
The magnetic fields generated by the earths north and south poles are divided into zones that differ from each other with respect to how the magnetic
fields appear.
The magnetic north can change by up to 4 degrees between zones and become noticeable across multiple zones. The compass zone must be set to the
correct zone for the compass to read accurately. Factors within the vehicle may affect the ability of the compass module to accurately read the
magnetic north. Calibrating the compass allows the compass module to compensate for vehicle factors that influence the accuracy of the compass.
NOTE: Outside factors such as bridges, steel structures, tall buildings and power lines also affect compass accuracy.
This pinpoint test is intended to diagnose the following:
-
Compass zone setting
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Compass calibration
