Isuzu 2008MY N Series User Manual

Engine Control System (4HK1) 1A-117
3
Observe the Engine Coolant Temperature (ECT)
Sensor parameter with a scan tool.
Is the ECT Sensor parameter more than the
specified value?
4.8 volts
Go to Step 4
Go to Diagnostic
Aids
4
1. Turn OFF the ignition.
2. Disconnect the ECT sensor harness
connector.
3. Connect a DMM between the signal circuit
(pin 1 of E-25) and a known good ground.
4. Turn ON the ignition, with the engine OFF.
Is the DMM voltage more than the specified
value?
5.5 volts
Go to Step 5 Go to Step 6
5
Important: The ECT sensor may be damaged if
the sensor signal circuit is shorted to a voltage
source.
1. Test the signal circuit between the ECM (pin
84 of E-12) and the ECT sensor (pin 1 of E-
25) for a short to battery or ignition voltage.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
—
Go to Step 15 Go to Step 14
6
Connect a 3-amp fused jumper wire between the
signal circuit and the low reference circuit (pins 1
and 2 of E-25).
Is the ECT Sensor parameter less than the
specified value?
0.1 volts
Go to Step 10 Go to Step 7
7
Connect a 3-amp fused jumper wire between the
signal circuit (pin 1 of E-25) and a known good
ground.
Is the ECT Sensor parameter less than the
specified value?
0.1 volts
Go to Step 9 Go to Step 8
8
1. Test the signal circuit between the ECM (pin
84 of E-12) and the ECT sensor (pin 1 of E-
25) for an open circuit or high resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
—
Go to Step 15 Go to Step 12
9
Notice: The ECT sensor shares the low reference
circuit with other sensors. A fault condition in the
low reference circuit may set DTCs on sensors that
share this circuit.
1. Test the low reference circuit between the
ECM (pin 109 of E-12) and the ECT sensor
(pin 2 of E-25) for an open circuit or high
resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
—
Go to Step 15 Go to Step 12
10
1. Test the signal circuit between the ECM (pin
84 of E-12) and the ECT sensor (pin 1 of E-
25) for a short to any 5 volts reference circuit.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
—
Go to Step 15 Go to Step 11
Step Action Value(s) Yes No
LG4HKED-WE-0871.book 117 ページ ２００７年１１月２９日 木曜日 午後６時２９分

Isuzu 2008MY N Series Specifications

General

Brand	Isuzu
Model	2008MY N Series
Category	Control Systems
Language	English