Sakai SV414, Shop Manual

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9-032
TROUBLESHOOTING
2-4. Propulsion
Check following items before troubleshooting.
No blown fuses and power is applied up to fuses.
When measuring voltage and current without disconnecting connectors, refer to “Measuring voltage and current
flowing using tester” (P.9-006 to P.9-008).
Check any ground circuit which belongs to components to be checked.
2-4-1. Machine moves neither forward nor backward 1/2
Parking brake switch must be released.
Brake pedal is not depressed.
Reference Fig.: 2-4-1
Check point Check/Cause Action
1. Servo Bypass Solenoid Disconnect harness and measure resistance of coil.
Standard resistance : 12.3
± 1.2
Ω
If measured resistance is abnormal, servo bypass
solenoid is faulty.
•
•
Replace servo bypass
solenoid.
2. Parking Brake Solenoid Disconnect harness and measure resistance of coil.
Standard resistance : 12.3
± 1.2
Ω
If measured resistance is abnormal, parking brake
solenoid is faulty.
•
•
Replace parking brake
solenoid.
3. Pump Neutral Relay
(A3)
(1) When starter switch is ON, measure voltage between
pump neutral relay terminal 1 inlet wire BrW and
chassis ground.
Standard voltage : 12 V or more
(2) When starter switch is ON, measure voltage between
pump neutral relay terminal 3 inlet wire GW and chassis
ground.
Standard voltage : 12 V or more
(3) When starter switch is ON, measure voltage between
pump neutral relay terminal 5 outlet wire LY and chassis
ground.
Standard voltage : 12 V or more
If above items (1) and (2) are OK and item (3) is NG,
pump neutral relay is faulty.
•
Replace pump neutral
relay (A3).
4. Pump Neutral Holding
Relay (A4)
(1) When starter switch is ON and F-R lever is “F” or “R”,
measure voltage between pump neutral holding relay
terminal 1 inlet wire LY and chassis ground.
Standard voltage : 12 V or more
(2) When starter switch is ON and F-R lever is “F” or “R”,
measure voltage between pump neutral holding relay
terminal 3 inlet wire R and chassis ground.
Standard voltage : 12 V or more
(3) When starter switch is ON and F-R lever is “F” or “R”,
measure voltage between pump neutral holding relay
terminal 5 outlet wire GW and chassis ground.
Standard voltage : 12 V or more
If above items (1) and (2) are OK and item (3) is NG,
pump neutral holding relay is faulty.
•
Replace pump neutral
holding relay (A4).
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•
•
•
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