KYMCO AK 550 Service Manual page 371

10..Brake System
AK 550
When using the DATA Analyze feature of the diagnostic tool with the ABS system
the front and rear wheel speed sensors should show speed when the wheels are
rotated.
Inspect the wheel speed sensors, rotors, wires, and connectors if the speed
doesn't show correctly.
Check the speed sensor to rotor clearance with a feeler gauge and make sure
that it is 0.3 - 1.2 mm (0.0012 - 0.048 in).
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