Composition And Operation Of Parts - Yamaha YP250A 1999 Supplementary Service Manual

ABS OUTLINE

COMPOSITION AND OPERATION OF PARTS

1. Wheel sensor and sensor ring
A wheel sensor is composed of magnet and coil
and installed with front and rear wheels' housings.
The sensor ring attached to front and rear cast
wheels have 36 serration each. The front end of
wheel sensor is close to the serration.
When the sensor rotor with serration rotates, the
flux generation from the wheel sensor magnet
changes to generate the alternating voltage in the
coil. The electronic control unit calculates the
wheel speed by detecting the repeating times per
unit period since this alternating voltage changes
the frequency proportioning to the wheel rotation
speed.
1 At high speed
2 At low speed
3 Wheel sensor
Sensor rotor
4
2. ABS warning light
If the failure occurred in the ABS system, the ABS
warning light alerts the rider by going on the ABS
warning light.
When the main switch is turned on, the system
goes on the light for about 2 seconds to check the
disconnection of ABS warning light and system
function, then it goes off.
It goes on while the starter switch is pushed to
check the disconnection.
CAUTION:
If the rear wheel is raced by lifting with the cen-
terstand or other means, the system may
judge as the malfunction to flashes or goes on
the ABS warning light.
In this case, turn the main switch off once and
restart the engine.
The system is normal if the ABS warning light
goes on and off in about 2 seconds.
1 ABS warning light
5
GEN
INFO