Doosan D35S-5 Service Manual page 162

Trouble diagnosis flow when engine is lack of power
Lack of power in
engine, Insufficient
injection quantity
Pump system
Injector system
ECU system
D439E Service Manual
Currently
malfunction
OK
Fuel system check flow
OK
Sensors, wirings check flow
OK
Check SCV resistance value
at 20℃, 7.9±0.25Ω(24V)
OK
Check injector
injection (Diagnosis equipment
Check the cylinder without any
vibration change at one cylinder
stop mode
OK
Check poor connection of ECU
ground and ECU connector
OK
Erase the
trouble code and previous
pump learned values with the
diagnosis equipment. Perform the
learning again at idle after
engine warm up.
Currently
malfunction
Check based on
each trouble code
Is "engine
lacks power"
corrected?
NG
NG
NG
Replace corresponding injector
NG
Repair or correct the wiring
and connection
OK
Completed
NG
Replace ECU
160
Ex)
Fix the single fail of sensor,
ECU, pump SCV and TWV
system
CKP (Crank shaft Position)
Sensor system
PC sensor system (rail
pressure sensor)
Accel sensor system
ECU sensor system (CPU
malfunction)
TWV system
Defect caused by FCCB
(fuel control for cylinder
balance) is processed by other
flow
OK
Completed
Replace supply pump
NG
Check injector
wiring
OK
Repair or replace
wiring
4. Fuel system