Isuzu 2008MY N Series Workshop Manual page 181

1A-178 Engine Control System (4HK1)
Step
1. Test the position sensor circuits (which ever
parameter did not indicate High at Step 6)
between the ECM (pins 93, 94 and 99 of E-12)
and the EGR valve (pins 2, 3 and 4 of E-15)
for the following conditions:
• An open circuit
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• A short to ground
• A short to the low reference circuit
• High resistance
2. Repair the circuit(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
EGR valve (pins 1, 2, 3, 4 and 5 of E-15)
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2. Repair the connection(s) as necessary.
Did you find and correct the condition?
1. Test the solenoid circuits between the ECM
(pins 103, 110 and 111 of E-12) and the EGR
valve (pins 6, 7 and 8 of E-15) for a short to
the EGR position sensor circuit(s).
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2. Repair the circuit(s) 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 poor
connections at the harness connector of the
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ECM (pins 87, 93, 94, 99 and 101 of E-12).
4. Repair the connection(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.
14
Did you complete the replacement?
Important:
programmed and learned.
15
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.
Notice: A history DTC will not clear. (Euro 4
specification)
3. Turn OFF the ignition for 30 seconds.
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4. Start the engine.
5. 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?
Action
Replacement ECM
all previously disconnected
within the conditions
Value(s)
—
—
—
—
—
must be
—
—
that you
Yes
Go to Step 16 Go to Step 13
Go to Step 16 Go to Step 12
Go to Step 16 Go to Step 14
Go to Step 16 Go to Step 15
Go to Step 16
Go to Step 16
Go to Step 3 Go to Step 17
No