Vehicle Demagnetizing

If the compass is inaccurate after calibration, vehicle magnetism may be too high and vehicle demagnetizing is necessary. Initially the vehicle is demagnetized at the manufacturer's plant. In most cases this is sufficient for the life of the vehicle. However, if after calibration the compass still is inaccurate, demagnetizing must be performed.

NOTE: The demagnetizing procedure must be followed exactly. Failure to do so may result in the vehicle being remagnetized.

NOTE: Whenever the demagnetizing equipment is being operated over the vehicle's surface, or within 1m (3 ft.) of the vehicle, the operator must maintain a constant, steady motion. Failure to do so may result in the vehicle being remagnetized.

The demagnetizing process requires the use of a demagnetizing coil commonly used by TV service technicians to demagnetize television tubes. Demagnetize the vehicle by sweeping over the compass sensor with a demagnetizing coil as follows:

1. Standing 1m (3 ft.) or more away from the vehicle, turn on the demagnetizing coil.

2. In one continuous motion make four passes over the compass sensor. The demagnetizer should be held 2-1/2 cm (1 inch) or less (but not touching) from the vehicle's roof.

3. After the fourth pass, and without stopping the motion of the demagnetizing coil, pull away from the vehicle.

4. When the demagnetizer coil is at least 1m (3 ft.) away from the vehicle, turn the demagnetizing coil off.

5. Perform the Zone Adjustment and Calibration Adjustment procedures as described in the Adjustments portion of this section.