Doosan V158TI Operation & Maintenance Manual page 215

When the System is Not Working
In the event that the engine governor system is not working properly, you can deduce the cause by performing
the test in the following chart.
Here, (+) and (-) represent the polarities of the measuring instrument. Using the method in the chart below, if
the test results are normal, there may be a problem in the actuator or the actuator wiring connections so the
actuator must be inspected.
Measured
Step
terminals
1 F (+) & E (-)
2 F (+) & E (-)
3 C & D
4 C & D
5 A & B
6 P (+) & G (-)
7 F (+) & A (-)
Time of
Normal value
measurement
E/G stopped DC 24V
E/G starting DC 15 or higher
300 ~ 1,200 
E/G stopped using test ohm-
1.5V or higher
when measured
E/G starting
with tester AC
voltmeter
3.8 ~ 4.5 
E/G stopped using test ohm-
Key S/W ON DC 9.5 ~ 10.5V Faulty control device
DC 9 ~ 15V
While in when normal
operation DC 1 ~ 3V when
abnormal
Presumed cause of fault
Battery failure
Faulty connection
Defective speed sensor
Damaged or incorrectly
connected speed sensor
meter
wiring
Gap between speed sen-
sor and ring gear too wide.
Defective speed sensor
Check line for short circuit
if measured value is less
than 3.8 
Check line for open circuit
meter if measured value is over
4.8 
Defective actuator
Low speed setting.
Short or open circuit in
actuator wiring connection
Actuator
- 27 -
Troubleshooting
Check battery line,
replace battery.
Check sensor line.
Replace speed sen-
sor.
Check actuator line for
short or open circuit.
Replace actuator
Replace controller.
Check speed settings.
Check actuator line.
Check actuator and
replace if faulty.