Isuzu 4HL1 Workshop Manual page 186

1A-184 Engine Control System
Step
Check the intermediate connector for fault.
1. Disconnect ECM side and injector side
connectors
connector.
2. Remove the intermediate connector from
the engine block.
3. Jumper the intermediate connector that
was connected to the injectors and
7
measure
intermediate
connected to the ECM.
Was the resistance within range?
Replace the intermediate connector.
8
Is the action complete?
Check the common 1 injector drive circuit
(intermediate connector to injector) for open
wiring or short.
1. Disconnect the injector side connectors
from the intermediate connector.
2. Disconnect harnesses from injectors for
9
cylinders 1 and 4.
3. Measure the resistance between injector
terminal and connector pin as well as
between connector pins.
Was the resistance within range?
Repair or replace the faulty harness.
10
Is the action complete?
Measure the resistance between injector
terminals (resistance of coil) for cylinders 1
11
and 4.
Was the resistance within range?
Repair or replace the faulty injector(s).
12
Is the action complete?
Check DTC158 will not be set again.
1. Restore the vehicle.
2. Using Tech 2, clear the DTC.
13
3. Bleed the air from the fuel system.
4. Perform test run and review the DTC.
Is DTC158 detected?
Review the DTC.
1. Restore the vehicle.
2. Using Tech 2, clear the DTC.
14
3. Perform test run and review the DTC.
Is DTC158 detected?
Action
from the intermediate
the resistance at
connector that
Value(s)
Pins 1-2/3/4
(jumpered:
pins 1-2/3/4):
0 Ω
(not jumpered):
∞ Ω
Pins 2-3/4
(jumpered:
pins 2-3/4):
the 0 Ω
was
(not jumpered):
∞ Ω
Pins 3-4
(jumpered:
pins 3-4): 0 Ω
(not jumpered):
∞ Ω
—
Cylinder 1
-pins 1:
0 Ω
Cylinder 4
-pins 4:
0 Ω
Pins 1-4: ∞ Ω
—
0.4 Ω
—
—
—
Yes
Go to Step 9
Go to Step 16
Go to Step 11
Verify repair and
go to Step 16
Go to Step 14
Go to Step 13
Refer to
Diagnostic Aids
and go to Step 2
Go to Step 15 Diagnostic Aids
No
Go to Step 8
—
Go to Step 10
—
Go to Step 12
—
Repair is
complete
Refer to