Isuzu 4HL1 Workshop Manual page 243

Step
Replace the intermediate connector.
6
Is the action complete?
Check the common 2 injector side connectors
drive circuit
injector) for open wiring or short.
1. Disconnect the injector side connector
from the intermediate connector.
2. Disconnect harnesses from the cylinder 2
7
or 3 injector.
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.
8
Is the action complete?
Measure the resistance between injector
terminals (resistance of coil) for cylinders 2
9
and 3.
Was the resistance within range?
Replace the faulty injector(s).
10
Is the action complete?
Check DTC278 will not be set again.
1. Restore the vehicle.
2. Using Tech 2, clear the DTC.
11
3. Bleed the air from the fuel system.
4. Perform test run and review the DTC.
Is DTC278 detected?
Review the DTC.
1. Restore the vehicle.
2. Using Tech 2, clear the DTC.
12
3. Perform test run and review the DTC.
Is DTC278 detected?
1. Replace the ECM.
IMPORTANT:
If necessary (for the vehicle equipped with
13
idle stop function), input the number of
startups to the replacing ECM.
Is the action complete?
Check DTC278 will not be set again.
1. Using Tech 2, clear the DTC.
14
2. Perform test run and review the DTC.
Is DTC278 detected?
Action
(intermediate connector
Value(s)
—
to
Cylinder 2-
pins 2:
0 Ω
Cylinder 3-
pins 3:
0 Ω
Pins 2-3: ∞ Ω
—
0.4 Ω
—
—
—
—
—
Engine Control System 1A-241
Yes
Go to Step 14
Go to Step 9
Verify repair and
go to Step 14
Go to Step 12
Go to Step 11
Refer to
Diagnostic Aids
and go to Step 2
Go to Step 13 Diagnostic Aids
Verify repair and
go to Step 14
Refer to
Diagnostic Aids
and go to Step 2
No
—
Go to Step 8
—
Go to Step 10
—
Repair is
complete
Refer to
—
Repair is
complete