Doosan D439E - Engine Control System Diagnostics

D439E Service Manual 4. Fuel system
165
Re
p
air the harness
Repair the short
harness
Below the standard
Engine stop
Injector ground
short
Measure
the ground resistance
between terminal and
body
OK
Replace the
injector
OK
Partial malfunctions
Stop the
injectors one by one
using diagnosis equipment,
Then, check any vibration or
smoke.
Replace the
corresponding
injector
Check injector harness. It
shouldn’t be +B short
Check
harness ground short
between ECU and
in
jecto
r
Re
p
lace ECU
OK
Short
Re
p
lace ECU
Yes
Does it
happen at test drive
after engine
restart?
Injector B+ is
short
Internal fail of
ECU
Short