Yamaha YP250A 1999 Supplementary Service Manual page 82

ANTI-LOCK BRAKE SYSTEM (ABS)
Checking 1 the hydraulic unit
(Resistance of solenoid valve/Continuity of
motor)
1. Measure:
S Resistance of solenoid valve (front side)
Connect the pocket tester (Ω X 1) to the termi-
nal of solenoid valve (front).
Tester's positive (+) lead ! Terminal 1
Tester's negative (–) lead ! Terminal 2
Solenoid valve resistance:
Less than 10 Ω at 20 _C
Out of specification ! Replace the hydraulic
unit
2. Measure:
S Resistance of solenoid valve (rear side)
Connect the pocket tester (Ω X 1) to the termi-
nal of solenoid valve (rear).
Tester's negative (–) lead ! Terminal 1
Tester's positive (+) lead ! Terminal 2
Solenoid valve resistance:
Less than 10 Ω at 20 _C
Out of specification ! Replace the hydraulic
unit.
3. Check:
S Insulation of solenoid valve
Connect the pocket tester (Ω X 1k) to the ter-
minal of solenoid valve and battery negative (–)
terminal.
Tester's positive (+) lead ! 1 2 3 4
Tester's negative (–) lead ! Battery negative
(–) terminal
If continuity is all right ! Replace the hydraulic
unit.
4. Check:
S Continuity of the motor (HU)
Connect the pocket tester (Ω X 1) to the termi-
nal of motor coupler.
Tester's positive (+) lead ! 1 terminal
Tester's negative (–) lead ! 2 terminal
Continuity is all right.
No continuity ! Replace the hydraulic unit.
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CHAS