Isuzu N 2008 Series Workshop Manual page 227

1A-224 Engine Control System (4JJ1)
Step
1. Turn OFF the ignition.
2. Disconnect the EGR valve harness connector.
3. Inspect
connections and corrosion at the harness
connector of the EGR valve (pins 1, 2, 3, 4, 5,
6, 7 and 8 of E15).
4. Disconnect the ECM harness connector.
5. Inspect
4
connections and corrosion at the harness
connector of the ECM (pins 87, 93, 94, 99,
101, 103, 110 and 111 of E12).
6. Test for an open circuit or high resistance on
each circuit.
7. Repair the connection(s) or circuit(s) as
necessary.
Did you find and correct the condition?
1. Test the solenoid circuits between the ECM
(pins 103, 110 and 111 of E12) and the EGR
valve (pins 6, 7 and 8 of E15) for the following
conditions:
• A short to ground
• A short to battery or ignition voltage
5
• A short circuit each other
• A short to the EGR position sensor
circuit(s)
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
Replace the EGR valve. Refer to EGR Valve and
EGR Cooler in Section 1F Emission Control.
6
Did you complete the replacement?
1. Reconnect
harness connector(s).
Notice: Ignition switch must be cycled before
clear the DTC.
2. Turn ON the ignition, with the engine OFF.
3. Turn OFF the ignition for 30 seconds.
4. Turn ON the ignition and clear the DTCs with
a scan tool.
7
Notice: A history DTC will not clear. (Euro 4
specification)
5. Turn OFF the ignition for 30 seconds.
6. Start the engine.
7. Operate the vehicle within the Conditions for
Running the DTC. You may also operate the
vehicle
observed from the Freeze Frame/ Failure
Records.
Did the DTC fail this ignition?
Observe the DTC Information with a scan tool.
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Are there any DTCs that you have not diagnosed?
Action
for an intermittent,
for an intermittent,
all previously disconnected
within the conditions
Value(s)
for poor
for poor
—
—
—
—
that you
—
Yes
Go to Step 7 Go to Step 5
Go to Step 7 Go to Step 6
Go to Step 7
Go to Step 2 Go to Step 8
Go to DTC List
No
—
System OK