Isuzu N 2008 Series Workshop Manual page 171

1A-168 Engine Control System (4JJ1)
Step
1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
2
4. Monitor the DTC Information with a scan tool.
Is DTC P0697 also set?
1. Start the engine and fully warm up (allow
engine coolant temperature to reach at least
80°C [176°F]).
2. Accelerate the engine between idle and
W.O.T. (accelerator pedal full travel) many
3
times while
Temperature Sensor 1 parameter with a scan
tool.
Is the Exhaust Temperature Sensor 1 parameter
more than the specified value?
1. Turn OFF the ignition.
2. Disconnect the exhaust temperature sensor 1
harness connector.
3. Connect a DMM between the signal circuit
4
(pin 2 of J34) and a known good ground.
4. Turn ON the ignition, with the engine OFF.
Is the DMM voltage more than the specified value?
Important: The exhaust temperature sensor 1 may
be damaged if the sensor signal circuit is shorted to
a voltage source.
1. Test the signal circuit between the ECM (pin
73 of J14) and the exhaust temperature
5
sensor 2 (pin 2 of J34) for a short to battery or
ignition voltage.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
Connect a 3-amp fused jumper wire between the
signal circuit and the low reference circuit (pins 1
and 2 of J34).
6
Is the Exhaust Temperature Sensor 1 parameter
less than the specified value?
Connect a 3-amp fused jumper wire between the
signal circuit (pin 2 of J34) and a known good
ground.
7
Is the Exhaust Temperature Sensor 1 parameter
less than the specified value?
1. Test the signal circuit between the ECM (pin
73 of J14) and the exhaust temperature
sensor 1 (pin 2 of J34) for an open circuit or
8 high resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
Action
observing the Exhaust
Value(s) Yes
—
Go to DTC P0697
4.8 volts
Go to Step 4
5.5 volts
Go to Step 5
—
Go to Step 15
0.1 volts
Go to Step 10
0.1 volts
Go to Step 9
—
Go to Step 15
No
Go to Step 3
Go to Diagnostic
Aids
Go to Step 6
Go to Step 14
Go to Step 7
Go to Step 8
Go to Step 12