Isuzu 2008MY N Series Workshop Manual page 144

Step
1. Test the cylinder #4 fuel injector circuit
between the fuel injector terminals and the in-
line harness connector for the following
conditions:
• An open circuit
13
• A short circuit each other
• High resistance
2. Repair the circuit(s) or replace the fuel injector
harness as necessary.
Did you find and correct the condition?
1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor
connection at the harness connector of the
14
ECM.
4. Repair the connection(s) as necessary.
Did you find and correct the condition?
Important: Replacement fuel injector must be
programmed.
Replace the cylinder #4 fuel injector. Refer to
15
Injector in Section 1D Engine Fuel.
Did you complete the replacement?
Important: Replacement
programmed and learned.
16
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement?
1. Reconnect
harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
17
5. Operate the vehicle within the Conditions for
Running the DTC. You may also operate the
vehicle within
observed from the Freeze Frame/Failure
Records.
Did the DTC fail this ignition?
Observe the DTC Information with a scan tool.
18
Are there any DTCs that you have not
diagnosed?
Action
ECM must
all previously disconnected
the conditions that
Engine Control System (4HK1)
Value(s)
—
—
—
be
—
—
you
—
Yes
Go to Step 17 Go to Step 15
Go to Step 17 Go to Step 16
Go to Step 17
Go to Step 17
Go to Step 3 Go to Step 18
Go to DTC List
1A-141
No
—
—
System OK