Dtc P0299 (Flash Code 65) - Isuzu N 2008 Series Workshop Manual

DTC P0299 (Flash Code 65)

Circuit Description
The boost pressure sensor is located in the air
induction tubing. The sensor is a transducer that varies
voltage according to changes in the air pressure inside
the air tubing. The ECM monitors the boost pressure
sensor signal for abnormal values. If the ECM detects
that the sensor signal is excessively low, this DTC will
set. This indicates excessive low boost pressure.
Condition for Running the DTC
• DTCs P0045, P0079, P0080, P0087, P0089,
P0091, P0092, P0093, P0102, P0103, P0107,
P0108, P0116, P0117, P0118, P0122, P0123,
P0192, P0193, P0201 - P0204, P0401, P0404,
P0409, P0560, P060B, P0638, P0651, P0697,
P1093, P1261, P1262, P1404, P2146, P2149,
P2227, P2228, P2229, P2453, P2527 and P2528
are not set.
• The ignition switch is ON.
• The engine speed is between 1600 to 3000 RPM.
• The fuel injection quantity is higher than a
predetermined range.
Condition for Setting the DTC
• The ECM detects that the boost pressure is lower
than 95 to 170 kPa (14 to 25 psi) for longer than 5
seconds.
Action Taken When the DTC Sets
• The ECM illuminates the MIL on the second
consecutive driving cycle when the diagnostic runs
and fails. Refer to DTC Type Definitions for Action
Taken When the DTC Sets - Type B. (Euro 4
specification)
• The ECM illuminates MIL when the diagnostic runs
and fails. Refer to DTC Type Definitions for Action
Taken When the DTC Sets - Type A. (Except Euro
4 specification)
Condition for Clearing the DTC
• Refer to DTC Type Definitions for Condition for
Clearing the MIL/ DTC - Type B. (Euro 4
specification)
Circuit/ System Testing DTC P0299
Step
Did you perform the Diagnostic System Check -
1 Engine Controls?
Action
Engine Control System (4JJ1)
• Refer to DTC Type Definitions for Condition for
Clearing the MIL/ DTC - Type A. (Except Euro 4
specification)
Diagnostic Aids
• Induction air leakage can cause a low boost
pressure condition. A whistling noise may be heard
if a component is allowing air to enter the induction
system.
• Check for cracked air tubing that may only open
during certain engine movement conditions.
• Misrouted vacuum hoses may set this DTC.
• Check the turbocharger nozzle control actuator or
wastegate valve
Turbocharger Assembly in Section 1J Induction.
• Use a scan tool to verify the integrity of the boost
pressure sensor signal. Compare the sensor
values under all load conditions for an excessively
low value.
• Fuel system problem (low fuel pressure condition)
may set this DTC.
• Loss of vacuum pressure or vacuum pump
problem sets this DTC.
Test Description
The numbers below refer to the step number on the
Circuit/ System Testing.
4. A skewed boost pressure sensor value (shifted to a
lower pressure) can set this DTC. The Boost Pressure
on the scan tool should read near Barometric Pressure
(BARO) with the ignition switch ON and engine OFF.
5. A skewed BARO sensor value (shifted to a higher
pressure) may indicate a wrong boost pressure. The
BARO on the scan tool should read near surrounding
barometric pressure.
Routing Reference: Vacuum Hose Routing Diagram
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Value(s) Yes
—
Go to Step 2
1A-137
for a sticking. Refer
No
Go to Diagnostic
System Check -
Engine Controls
to