Isuzu N 2008 Series Workshop Manual page 131

1A-128 Engine Control System (4JJ1)
Step
1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
2
4. Monitor the DTC Information with a scan tool.
Does the DTC fail this ignition?
1. Turn OFF the ignition.
2. Disconnect the cylinder #1 and #4 fuel injector
harness connector.
3. Measure the resistance of the charge voltage
3
circuit between the cylinder #1 and #4 fuel
injector (pin 2 of E5 and pin 2 of E8).
Is the resistance less than the specified value?
1. Connect a DMM between the cylinder #4
charge voltage circuit (pin 2 of E8) and a
known good ground.
4
2. Turn ON the ignition, with the engine OFF.
Is the DMM voltage less then the specified value?
Connect a DMM between the cylinder #4 solenoid
control circuit (pin 1 of E8) and a known good
5
ground.
Is the DMM voltage less than the specified value?
Is the DMM voltage more than the specified value
6
at Step 5?
Repair the open circuit or high resistance on the
charge voltage circuit between the ECM (pin 121 of
7
E12) and the cylinder #4 fuel injector (pin 2 of E8).
Did you complete the repair?
1. Test the control circuit between the ECM (pin
117 of E12) and the cylinder #4 fuel injector
(pin 1 of E8) for a short to the common 1
8 charge voltage circuit.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
1. Test the control circuit between the ECM (pin
117 of E12) and the cylinder #4 fuel injector
(pin 1 of E8) for a short to battery or ignition
9 voltage.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
1. Test the control circuit between the ECM (pin
117 of E12) and the cylinder #4 fuel injector
(pin 1 of E8) for an open circuit or high
10 resistance.
2. Repair the connection(s) as necessary.
Did you find and correct the condition?
1. Inspect for an intermittent and for poor
connections at the harness connector of the
cylinder #4 fuel injector (pins 1 and 2 of E8).
11
2. Repair the connection(s) as necessary.
Did you find and correct the condition?
Action Value(s) Yes
—
Go to Step 3
1.0 Ω
Go to Step 4
1.0 volt
Go to Step 5
16.0 volts
Go to Step 6
12.0 volts
Go to Step 11
—
Go to Step 15
—
Go to Step 15
—
Go to Step 15
—
Go to Step 15
—
Go to Step 15
No
Go to Diagnostic
Aids
Go to Step 7
Go to Step 8
Go to Step 9
Go to Step 10
—
Go to Step 14
Go to Step 14
Go to Step 12
Go to Step 13