Isuzu N 2008 Series Workshop Manual page 141

1A-138 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 P0045, P0107, P0108, P2227, P2228 or
P2229 also set?
1. Inspect the following for possible causes of
low boost pressure.
• Air leakage around the boost pressure
sensor or objects that block the sensor
hole.
• Air leaking around any of the air induction
tubing between the turbocharger and
intake manifold. Check for damaged
components and for loose clamps.
• Misrouted,
turbocharger nozzle control actuator
vacuum hose.
• Turbine shaft binding causing lower
turbocharger
Refer to Turbocharger Assembly in
Section 1J Induction.
• Turbocharger nozzle control actuator or
solenoid valve for a stuck condition.
Perform
3
Control with a scan tool. Refer to
Turbocharger Assembly in Section 1J
Induction.
• Wastegate valve for a stuck condition.
Refer to Turbocharger Assembly in
Section 1J Induction.
• Intake throttle valve sticking. Perform the
Intake Throttle Solenoid Control with a
scan tool.
• Restricted air cleaner element, restricted
or collapsed air tubing between the air
cleaner and the boost pressure sensor.
• Oil in the air induction tubing causing an
incorrect boost pressure sensor signal.
When there is adhesion of oil inside of
the tubing, intercooler or turbocharger it
needs to be wiped off.
2. Repair or replace as necessary.
Did you find and correct the condition?
1. Turn ON the ignition, with the engine OFF.
2. Observe the Boost Pressure and Barometric
Pressure (BARO) with a scan tool.
4
Does the scan tool indicate that the difference
between the Boost Pressure and BARO is more
than the specified value?
Compare the BARO value to the range specified in
the altitude vs. barometric pressure table. Refer to
5
Altitude vs Barometric Pressure.
Is the BARO parameter within the range specified?
Action
disconnected or kinked
shaft spinning speeds.
the Turbocharger Solenoid
Value(s) Yes
—
Go to Applicable
DTC
—
Go to Step 10
10 kPa (1.5
psi)
Go to Step 5
—
Go to Step 6
No
Go to Step 3
Go to Step 4
Go to Diagnostic
Aids
Go to Step 7