Isuzu 4HL1 Workshop Manual page 254

1A-252 Engine Control System
Symptom Diagnosis Chart 1 (2/2)
Check item
EGR system
Exhaust brake
Catalyst
Starter switch
Starter cut relay
Starter relay
Starter
AP sensor
Idle position sensor
VS sensor
Idle up volume
Freezer switch
QWS switch
Main relay
A/C switch
A/C relay
PTO accelerator sensor
PTO switch
Others/notes
Poor startability
Symptom
C-5
C-6
D-7
B-2
B-4
B-5
D-13
A-3
B-1
A-5
C-8
B-3
B-3
B-5
B-3
B-6
A-4
B-3
Easy engine
Faulty idling
stall
LNW21AXF002501-X