Isuzu 2008MY N Series Workshop Manual page 290

Step
1. Turn OFF the ignition.
2. Disconnect the exhaust differential pressure
sensor harness connector.
3. Inspect for
connections and corrosion at the harness
connector of the exhaust differential pressure
sensor (pins 1, 2 and 3 of J-33).
4. Disconnect the ECM harness connector.
5. Inspect for
5
connections and corrosion at the harness
connector of the ECM (pins 67, 79 and 80 of
J-14).
6. Test each sensor circuit between the ECM and
the exhaust differential pressure sensor for
high resistance.
7. Repair the connection(s) or circuit(s) as
necessary.
Did you find and correct the condition?
Replace the exhaust differential pressure sensor.
Refer to Exhaust Differential Pressure Sensor in
6
Section 1G Engine Exhaust.
Did you complete the replacement?
1. Reconnect
harness connector(s) or components.
2. Turn ON the ignition for 30 seconds. DO NOT
start the engine. (This is to relearn exhaust
differential pressure sensor.)
3. Clear the DTC and reset the DPD Status with
7
a scan tool.
4. Turn OFF the ignition for 30 seconds.
5. Perform the DPD Regeneration with a scan
tool. If the DPD filter was replaced at Step 4,
skip to Step 9.
Did you complete the action?
1. Observe the
parameter with a scan tool. Make sure the
temperature is less than 150 °C (302 °F). If
more than 150 °C (302 °F), let increase 1500
RPM without load. (Turn the idle up control
knob clockwise.)
2. Accelerate the engine to W.O.T. (accelerator
8
pedal full travel) and read the Exhaust
Differential Pressure parameter when the
Exhaust Temperature 1 parameter is reached
to 200 °C (392 °F).
Is the Exhaust Differential Pressure parameter
more than the specified value?
Observe the DTC Information with a scan tool.
9
Are there any DTCs that you have not
diagnosed?
Action
an intermittent, for
an intermittent, for
all previously disconnected
Exhaust Temperature
Engine Control System (4HK1)
Value(s)
poor
poor
—
—
—
1
1.0 kPa
—
Yes
Go to Step 7 Go to Step 6
Go to Step 7
Go to Step 8
Go to Step 9 Go to Step 2
Go to DTC List
1A-287
No
—
—
System OK