Isuzu 2008MY N Series Workshop Manual page 193

1A-190 Engine Control System (4HK1)
Step
1. Turn OFF the ignition.
2. Disconnect the exhaust temperature sensor 2
harness connector.
4
3. Turn ON the ignition, with the engine OFF.
Is the Exhaust
parameter more than the specified value?
1. Test the signal circuit between the ECM (pin
74 of J-14) and the exhaust temperature
sensor 2 (pin 2 of J-35) 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 2. 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 74 and 79 of J-14) for
7
corrosion.
4. Repair or
necessary.
Did you find and correct the condition?
Important:
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
observed from the 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?
Circuit/ System Testing DTC P042D
Step
Did you perform the Diagnostic System Check
1
- Engine Controls?
Action
Temperature Sensor
clean the connection(s)
Replacement ECM
all previously disconnected
within the conditions
Action
Value(s)
4.5 volts
2
—
—
—
as
must be
—
—
that you
—
Value(s)
—
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
Yes
Go to Diagnostic
System Check -
Go to Step 2 Engine Controls
No
—
—
System OK
No