Isuzu 2008MY N Series Workshop Manual page 186

Step
1. Turn OFF the ignition.
2. Disconnect the exhaust temperature sensor 1
harness connector.
4
3. Turn ON the ignition, with the engine OFF.
Is the Exhaust Temperature
parameter more than the specified value?
1. Test the signal circuit between the ECM (pin
73 of J-14) and the exhaust temperature
sensor 1 (pin 2 of J-34) for the following
conditions:
• A short to ground
5
• A short to the low reference circuit
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
Replace the exhaust temperature sensor 1. Refer
to Exhaust Temperature Sensor in Section 1G
6
Engine Exhaust.
Did you complete the replacement?
1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect connections at the harness connector
of the ECM (pins 73 and 79 of J-14) for
7
corrosion.
4. Repair or
necessary.
Did you find and correct the condition?
Important: Replacement
programmed and learned.
8
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.
9
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.
10
Are there any DTCs that you have not
diagnosed?
Action
Sensor
clean the connection(s)
ECM must
all previously disconnected
the conditions that
Engine Control System (4HK1)
Value(s)
4.5 volts
1
—
—
—
as
be
—
—
you
—
Yes
Go to Step 6 Go to Step 5
Go to Step 9 Go to Step 7
Go to Step 9
Go to Step 9 Go to Step 8
Go to Step 9
Go to Step 3 Go to Step 10
Go to DTC List
1A-183
No
—
—
System OK