Isuzu 4HL1 Workshop Manual page 112

1A-110 Engine Control System
Step
Repair or replace the faulty harness.
15
Is the action complete?
Check the ECT sensor.
1. Disconnect the ECT sensor.
2. Provide temperature change on the
thermosensitive element of the ECT
16
sensor and measure the resistance
between the sensor connector pins.
Was the resistance within range?
Replace the ECT sensor.
17
Is the action complete?
Review the DTC.
1. Certainly connect the ECT sensor and
ECM connectors.
18
2. Using Tech 2, clear the DTC.
3. Perform test run and review the DTC.
Is DTC23 detected?
1. Replace the ECM.
IMPORTANT:
If necessary (for the vehicle equipped with
19
idle stop function), input the number of
startups to the replacing ECM.
Is the action complete?
Check DTC23 will not be set again.
1. Using Tech 2, clear the DTC.
20
2. Perform test run and review the DTC.
Is DTC23 detected?
Characteristics of ECT Sensor (reference)
[Thermistor Characteristics]
30
20
10
7.0
5.0
3.0
2.0
1.0
0.7
0.5
0.3
0.2
0.1
-20 0
Engine Coolant Temperature ( C)
Action
20 40 60 80 100 120
LNW21ASH000901-X
Value(s)
Verify repair and
—
go to Step 20
See graph
Go to Step 18
Verify repair and
—
go to Step 18
—
Go to Step 19
—
Verify repair and
go to Step 20
—
Refer to
Diagnostic Aids
and go to Step 2
Yes No
Go to Step 17
Refer to
Diagnostic Aids
Repair is
complete
—
—
—