8. Fuel system
146
System inoperative
If the engine governing system does not function, the
fault may be determined by performing the voltage tests
described in steps 1, 2 and 3. (+) and (-) refer to meter
polarity. If normal values should be indicated as a result
of following the troubleshooting steps, the fault may be
with the actuator or the wiring to the actuator. In that
case, check the actuator.
Ste
p
Terminal
When to Take
the Reading
Normal read-
ings
Probable Cause of Abnormal Read-
ing
Solution
1
F(+) & E(-)
When the
engine stopped
DC 24V
1. Check battery line
2. Replace battery
2
F(+) & E(-)
When starting
the engine
DC 15V or
above
1. Low battery voltage
1. Check battery line
2. Wiring error
2. Replace battery
3
C & D
When the
engine stopped
300~1200
Ω
(tester ohmme-
ter)
1. Defective speed sensor
1. Check sensor line
2. Improper or defective wiring to the
speed sensor
2. Replace speed sen-
sor
4
C & D
When starting
the engine
1.5V or above
(tester AC volt-
meter)
1. The gap between speed sensor and
gear teeth too great.
1. Check sensor line
2. Defective speed sensor
2. Replace speed sen-
sor
5
A & B
When the
engine stopped
3.8~4.5
Ω
(tes-
ter ohmmeter)
1. If the voltage reading is below
3.8
Ω
=> Short
1. Check short/open
actuator
2. If the voltage reading is above
4.8
Ω
=> Open wire
2. Replace actuator
3. Defective actuator
6
P(+) & G(-)
KEY S/W ON
DC 9.5~10.5V
Defective speed controller
Replace controller
7
F(+) & A(-)
When starting
the engine
DC 9~15V in
normal condi-
tions DC 1~3V
in abnormal
conditions
1. Speed adjustment set too low.
1. Check speed setting
2. Short/open in actuator wiring
2. Check actuator line
3. Actuator
3. Replace actuator
when found to be
defective
