2007 ISUZU KB P190 engine mount

Engine Control System (4JH1) 6E-53
DTC
(Symptom Code) Flash
Code MIL
Status DTC Name on
scan tool Condition for
Running the DTC Condition for
Setting the DTC Possible Cause
P0243
(3) 64 ON Turbocharger
W aste gate
Solenoid Boost
Solenoid Circuit •
The ignition switch
is ON.
• The BARO is
between 0 hPa and
3500 hPa.
• The IAT is between
-50°C (-58 °F) and
200°C (392°F).
• The ECT is
between -50°C (-
58 °F) and 150°C
(302°F).
•
The ECM detects
that the vacuum
pressure is 50 hPa
lower than the
desired vacuum
pressure for 3
seconds.
•
Vacuum pressure sensor circuits
are high resistance.
• Faulty vacuum hoses
• Misrouted vacuum hoses.
• Faulty vacuum pressure sensor.
• Faulty turbocharger solenoid
valve.
• Faulty vacuum regulating valve.
• Faulty turbocharger wastegate
valve.
• Faulty ECM.

P0243 (4) 64 ON Turbocharger
W aste gate
Solenoid Boost
Solenoid Circuit
Low Voltage •
The ignition switch
is ON.
•
The ECM detects
that the low voltage
condition on the
turbocharger
solenoid valve
control circuit for
longer than 3
seconds when the
solenoid valve is
commanded OFF.
•
ECM (10A) fuse (EB1) open.
• Turbocharger solenoid valve
ignition voltage feed circuit is
open circuit or high resistance.
• Turbocharger solenoid valve
control circuit is open circuit,
high resistance or short to
ground.
• Poor harness connector
connection.
• Faulty turbocharger solenoid
valve.
• Faulty ECM.

P0243 (5) 64 ON Turbocharger
W astegate
Solenoid Boost
Solenoid Circuit •
The ignition switch
is ON.
• The BARO is
between 0 hPa and
3500 hPa.
• The IAT is between
-50°C (-58 °F) and
200°C (392°F).
• The ECT is
between -50°C (-
58 °F) and 150°C
(302°F).
•
The ECM detects
that the vacuum
pressure is 50 hPa
higher than the
desired vacuum
pressure for 3
seconds.
•
Vacuum pressure sensor low
reference circuit is high
resistance.
• Faulty vacuum hoses
• Misrouted vacuum hoses.
• Faulty vacuum pressure sensor.
• Faulty turbocharger solenoid
valve.
• Faulty vacuum regulating valve.
• Faulty turbocharger wastegate
valve.
• Faulty ECM.

P0243 (6) 64 ON Turbocharger
W aste gate
Solenoid Boost
Solenoid Circuit •
The ignition switch
is ON.
• The ECT is
between -50°C (-
58 °F) and 150°C
(302°F).
• The EGR solenoid
valve control is
OFF.
• The MAF sensor
DTC P0100 is not
set.
• The vacuum
pressure sensor
DTC P0105 is not
set.
• The IAT sensor
DTC P0110 is not
set.
•
The ECM detects
that the MAF
amount is 56
mg/strk higher than
the desired MAF for
3 seconds.
•
Faulty turbocharger wastegate
valve.
• MAF sensor low reference circuit
is high resistance.
• Faulty EGR valve vacuum
control system.
• Faulty EGR valve.
• Faulty EGR solenoid valve.
• Faulty EGR solenoid valve
vacuum hose routing.
• Faulty MAF sensor.


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ISUZU KB P190 2007

6E-56 Engine Control System (4JH1)
DTC
(Symptom Code) Flash
Code MIL
Status DTC Name on
scan tool Condition for
Running the DTC Condition for
Setting the DTC Possible Cause
P0380
(4) 66 ON Glow Plug Relay
Control Circuit Low
Voltage •
The ignition switch
is ON. •
The ECM detects
that the low voltage
condition on the
glow relay control
circuit for longer
than 3 seconds
when the relay is
commanded OFF.
•
ECM (10A) fuse (EB1) open.
• Glow relay ignition voltage feed
circuit on coil side is open circuit
or high resistance.
• Glow relay control circuit is open
circuit, high resistance or short
to ground.
• Glow relay is poor installation.
• Faulty glow relay.
• Faulty ECM.

P0380 (8) 66 ON
Glow Plug Relay
Control Circuit
High Voltage •
The ignition switch
is ON. •
The ECM detect
that the high
voltage condition on
the glow relay
control circuit for
longer than 1
second when the
relay is commanded
ON.
•
Glow relay control circuit is short
to battery or ignition voltage
circuit.
• Faulty glow relay.
• Faulty ECM.

P0381 (4) 67 ON Glow Plug
Indicator Circuit
Low Voltage •
The ignition switch
is ON.
•
The ECM detects
that the low voltage
condition on the
glow indicator lamp
control circuit for
longer than 3
seconds when the
indicator lamp is
commanded OFF.
•
Meter (15A) fuse (C-14) open.
• Glow indicator lamp ignition
voltage feed circuit is open
circuit or high resistance.
• Glow indicator lamp control
circuit is open circuit, high
resistance or short to ground.
• Poor harness connector
connection.
• Glow indicator lamp bulb burned
out.
• Faulty instrument panel cluster
(meter assembly).
• Faulty ECM.

P0381 (8) 67 ON Glow Plug
Indicator Circuit
High Voltage •
The ignition switch
is ON. •
The ECM detects
that the high
voltage condition on
the glow indicator
lamp control circuit
for longer than 1
second when the
indicator lamp is
commanded ON.
•
Glow indicator lamp control
circuit is short to battery or
ignition voltage circuit.
• Faulty instrument panel cluster
(meter assembly).
• Faulty ECM.

P0400 (3) 32 ON Exhaust Gas
Recirculation
(EGR) System
Performance •
The ignition switch
is ON.
• The engine is
running.
• The BARO is
between 850 hPa
and 1100 hPa.
• The IAT is between
15°C (59°F) and
100°C (212°F).
• The ECT is
between 35°C
(95°F) and 100°C
(211°F).
•
The ECM detects
that the MAF
amount is 150
mg/strk lower than
the desired MAF for
60 seconds.
•
MAF sensor circuits are high
resistance.
• MAF sensor signal circuit is short
to IAT sensor signal circuit.
• Intake air leakage.
• Intake duct disconnected.
• Intake system is obstructed.
• Faulty turbocharger.
• Faulty exhaust system.
• Faulty EGR valve vacuum
control system.
• Faulty EGR valve.
• Faulty EGR solenoid valve.
• Faulty EGR solenoid valve
vacuum hose routing.
• Faulty MAF sensor.


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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-57
DTC
(Symptom Code) Flash
Code MIL
Status DTC Name on
scan tool Condition for
Running the DTC Condition for
Setting the DTC Possible Cause
P0400
(4) 32 ON Exhaust Gas
Recirculation
(EGR) Solenoid
Circuit Low
Voltage •
The ignition switch
is ON.
•
The ECM detects
that the low voltage
condition on the
EGR solenoid valve
control circuit for
longer than 3
seconds when the
solenoid valve is
commanded OFF.
•
ECM (10A) fuse (EB1) open.
• EGR solenoid valve ignition
voltage feed circuit is open
circuit or high resistance.
• EGR solenoid valve control
circuit is open circuit, high
resistance or short to ground.
• Poor harness connector
connection.
• Faulty EGR solenoid valve.
• Faulty ECM.

P0400 (5) 32 ON Exhaust Gas
Recirculation
(EGR) System
Performance •
The ignition switch
is ON.
• The engine is
running.
• The BARO is
between 850 hPa
and 1100 hPa.
• The IAT is between
15°C (59°F) and
100°C (212°F).
• The ECT is
between 35°C
(95°F) and 100°C
(211°F).
•
The ECM detects
that the MAF
amount is 150
mg/strk higher than
the desired MAF for
60 seconds.
•
MAF sensor low reference circuit
is high resistance.
• Faulty EGR valve vacuum
control system.
• Faulty EGR valve.
• Faulty vacuum pump
• Faulty EGR solenoid valve.
• Faulty EGR solenoid valve
vacuum hose routing.
• Faulty MAF sensor.
• Faulty ECM.

P0400 (8) 32 ON Exhaust Gas
Recirculation
(EGR) Solenoid
Circuit High
Voltage
•
The ignition switch
is ON.
•
The ECM detects
that the high
voltage condition on
the EGR solenoid
valve control circuit
for longer than 3
seconds when the
solenoid valve is
commanded ON.
•
EGR solenoid valve control
circuit is short to battery or
ignition voltage circuit.
• Faulty EGR solenoid valve.
• Faulty ECM.

P0500 (1) 24 ON Vehicle Speed
Sensor (VSS)
Circuit
•
The ignition switch
is ON. •
The ECM detects
that the vehicle
speed is higher
than 200 km/h (125
MPH) for 5
seconds.
•
Vehicle speed too high.
• Electrical interference.
• Magnetic interference.
• Faulty A/T VSS. (2W D with A/T)
• Faulty VSS. (Except 2W D with
A/T)
• Faulty ECM.

P0500 (A) 24 ON Vehicle Speed
Sensor (VSS)
Circuit
•
The ignition switch
is ON. •
The ECM detects
that the vehicle
speed sensor signal
frequency is too
high for 0.6
seconds. •
Electrical interference.
• Magnetic interference.
• Faulty A/T VSS. (2W D with A/T)
• Faulty VSS. (Except 2W D with
A/T)
• Faulty ECM.


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ISUZU KB P190 2007

6E-66 Engine Control System (4JH1)
DTC P0100 (Symptom Code 7) (Flash Code 65)
Circuit Description
The mass air flow (MAF) sensor is an air flow meter that
measures the amount of air that enters the engine. It is
fitted between the air cleaner and turbocharger. A small
quantity of air that enters the engine indicates
deceleration or idle speed. A large quantity of air that
enters the engine indicates acceleration or a high load
condition. The MAF sensor has the following circuits.
• Ignition voltage circuit
• 5 volts reference circuit
• Low reference circuit
• MAF sensor signal circuit
The engine control module (ECM) provides 5 volts
reference voltage through the reference circuit to the
MAF sensor. The ECM monitors the voltage on the 5
volts reference circuit. If the ECM detects an
excessively high MAF sensor 5 volts reference voltage,
this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.
Condition for Setting the DTC
• The ECM detects that the MAF sensor 5 volts
reference circuit voltage is more than 5.2 volts fo
r
0.5 seconds.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
• The ECM uses a MAF substitution of 1600 mg/strk
for engine control.
• The ECM uses an EGR solenoid valve control
substitution of 10%.
Condition for Clearing the MIL/DTC
• The ECM turns OFF the MIL when the diagnostic
runs and does not fail.
• A history DTC clears after 40 consecutive driving
cycles without a fault. Or clear with the scan tool.
Diagnostic Aids
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
Notice: • The MAF Sensor parameter on the scan tool will
only update with engine running.
Test Description
The number below refers to the step number on the
diagnostic table.
3. If the MAF sensor 5 volts reference circuit between
the ECM and the sensor is normal, the sensor signal
voltage low DTC P0100 (Symptom Code B) will set.

DTC P0100 (Symptom Code 7) (Flash Code 65)
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or Engine Control Module (ECM)
Connector End Views

Step Action Value(s) Yes No
1 Did you perform the Diagnostic System Check-
Engine Controls? 
Go to Step 2 Go to Diagnostic
System Check-
Engine Controls
2 1. Install the scan tool. 2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the Diagnostic Trouble Code (DTC) Information with the scan tool.
Does the DTC fail this ignition? 

Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition. 2. Disconnect the mass air flow (MAF) sensor harness connector.
3. Start the engine and let idle for 30 seconds.
4. Monitor the DTC Information with the scan tool.
Does DTC P0100 (Symptom Code B) set, but not
DTC P0100 (Symptom Code 7)? 

Go to Step 5 Go to Step 4

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ISUZU KB P190 2007

6E-68 Engine Control System (4JH1)
DTC P0100 (Symptom Code 9) (Flash Code 65)
Circuit Description
The mass air flow (MAF) sensor is an air flow meter that
measures the amount of air that enters the engine. It is
fitted between the air cleaner and turbocharger. A small
quantity of air that enters the engine indicates
deceleration or idle speed. A large quantity of air that
enters the engine indicates acceleration or a high load
condition. The MAF sensor has the following circuits.
• Ignition voltage circuit
• 5 volts reference circuit
• Low reference circuit
• MAF sensor signal circuit
The engine control module (ECM) provides 5 volts
reference voltage through the reference circuit to the
MAF sensor. The ECM monitors the voltage on the 5
volts reference circuit. If the ECM detects an
excessively low MAF sensor 5 volts reference voltage,
this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.
Condition for Setting the DTC
• The ECM detects that the MAF sensor 5 volts
reference circuit voltage is less than 4.6 volts fo
r
0.5 seconds.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
•
The ECM uses a MAF substitution of 1600 mg/strk
for engine control.
• The ECM uses an EGR solenoid valve control
substitution of 10%.
Condition for Clearing the MIL/DTC
• The ECM turns OFF the MIL when the diagnostic
runs and does not fail.
• A history DTC clears after 40 consecutive driving
cycles without a fault. Or clear with the scan tool.
Diagnostic Aids
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
Notice: • The MAF Sensor parameter on the scan tool will
only update with engine running.
Test Description
The number below refers to the step number on the
diagnostic table.
3. If the MAF sensor 5 volts reference circuit between
the ECM and the sensor is normal, the sensor signal
voltage low DTC P0100 (Symptom Code B) will set.

DTC P0100 (Symptom Code 9) (Flash Code 65)
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or Engine Control Module (ECM)
Connector End Views

Step Action Value(s) Yes No
1 Did you perform the Diagnostic System Check-
Engine Controls? 
Go to Step 2 Go to Diagnostic
System Check-
Engine Controls
2 1. Install the scan tool. 2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the Diagnostic Trouble Code (DTC) Information with the scan tool.
Does the DTC fail this ignition? 

Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition. 2. Disconnect the mass air flow (MAF) sensor harness connector.
3. Start the engine and let idle for 30 seconds.
4. Monitor the DTC Information with the scan tool.
Does DTC P0100 (Symptom Code B) set, but not
DTC P0100 (Symptom Code 9)? 

Go to Step 5 Go to Step 4
4 1. Test the 5 volts reference circuit between the engine control module (ECM) (pin 83 of C-57
connector) and the MAF sensor (pin 4 of C-116
connector) for the following conditions: • A short to ground
• A short to the low reference circuit
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 7 Go to Step 6

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ISUZU KB P190 2007

6E-70 Engine Control System (4JH1)
DTC P0100 (Symptom Code B) (Flash Code 65)
Circuit Description
The mass air flow (MAF) sensor is an air flow meter that
measures the amount of air that enters the engine. It is
fitted between the air cleaner and turbocharger. A small
quantity of air that enters the engine indicates
deceleration or idle speed. A large quantity of air that
enters the engine indicates acceleration or a high load
condition. The MAF sensor has the following circuits.
• Ignition voltage circuit
• 5 volts reference circuit
• Low reference circuit
• MAF sensor signal circuit
The engine control module (ECM) monitors the MAF
sensor signal for voltage outside the normal range o
f
the MAF sensor. If the ECM detects an excessively low
MAF sensor signal voltage, this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.
• The engine is running.
Condition for Setting the DTC
• The ECM calculated MAF is lower than -18.6 kg/h
for 5 seconds. This indicates the ECM detects that
the MAF sensor signal voltage is smaller than a
predetermined range during engine run.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
• The ECM uses a MAF substitution of 1600 mg/strk
for engine control.
• The ECM uses an EGR solenoid valve control
substitution of 10%.
Condition for Clearing the MIL/DTC
• The ECM turns OFF the MIL that the diagnostic
runs and does not fail.
• A history DTC clears after 40 consecutive driving
cycles without a fault. Or clear with the scan tool.
Diagnostic Aids
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
Notice: • W rong direction of MAF sensor installation will
cause this DTC to set.
• Contaminated or restricted MAF sensor will cause
this DTC to set.
• The MAF Sensor parameter on the scan tool will
only update with engine running.
Test Description
The number below refers to the step number on the
diagnostic table.
7. If the MAF sensor signal circuit between the ECM
and the sensor is short to ground or any low reference
circuits, the sensor 5 volts reference voltage low DTC
P0100 (Symptom Code 9) will set.
8. If the MAF sensor signal circuit between the ECM
and the sensor is normal, the sensor signal voltage high
DTC P0100 (Symptom Code C) will set.

DTC P0100 (Symptom Code B) (Flash Code 65)
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or Engine Control Module (ECM)
Connector End Views

Step Action Value(s) Yes No
1 Did you perform the Diagnostic System Check-
Engine Controls? 
Go to Step 2 Go to Diagnostic
System Check-
Engine Controls
2 1. Install the scan tool. 2. Turn OFF the ignition for 30 seconds.
3. Start the engine and let idle for 30 seconds.
4. Monitor the Diagnostic Trouble Code (DTC) Information with the scan tool.
Does the DTC fail this ignition? 

Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition. 2. Inspect the ECM (10A) fuse (EB-4) in the engine room fuse block.
Is the ECM (10A) fuse (EB-4) open? 

Go to Step 4 Go to Step 5
4 Replace the ECM (10A) fuse (EB-4). If the fuse continues to open, repair the short to ground on one
of the circuits that is fed by the ECM (10A) fuse (EB-
4) or replace the shorted attached component fed by
the ECM (10A) fuse (EB-4).
Did you complete the repair? 

Go to Step 17 

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-73
DTC P0100 (Symptom Code C) (Flash Code 65)
Circuit Description
The mass air flow (MAF) sensor is an air flow meter that
measures the amount of air that enters the engine. It is
fitted between the air cleaner and turbocharger. A small
quantity of air that enters the engine indicates
deceleration or idle speed.
A large quantity of air that
enters the engine indicates acceleration or a high load
condition. The MAF sensor has the following circuits.
• Ignition voltage circuit
• 5 volts reference circuit
• Low reference circuit
• MAF sensor signal circuit
The engine control module (ECM) monitors the MAF
sensor signal for voltage outside the normal range o
f
the MAF sensor. If the ECM detects an excessively high
MAF sensor signal voltage, this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.
• The engine is running.
Condition for Setting the DTC
• The ECM calculated MAF is higher than 984 kg/h
for 10 seconds. This indicates the ECM detects
that the MAF sensor signal voltage is higher than a
predetermined range during engine run.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
• The ECM uses a MAF substitution of 1600 mg/strk
for engine control.
• The ECM uses an EGR solenoid valve control
substitution of 10%.
Condition for Clearing the MIL/DTC
• The ECM turns OFF the MIL when the diagnostic
runs and does not fail.
• A history DTC clears after 40 consecutive driving
cycles without a fault. Or clear with the scan tool.
Diagnostic Aids
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
Notice: • The MAF Sensor parameter on the scan tool will
only update with engine running.
Test Description
The number below refers to the step number on the
diagnostic table.
3. If the MAF sensor signal circuit between the ECM
and the sensor is normal, the sensor signal voltage lo
w
DTC P0100 (Symptom Code B) will set.

DTC P0100
(Symptom Code C) (Flash Code 65)
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or Engine Control Module (ECM)
Connector End Views

Step Action Value(s) Yes No
1 Did you perform the Diagnostic System Check-
Engine Controls? 
Go to Step 2 Go to Diagnostic
System Check-
Engine Controls
2 1. Install the scan tool. 2. Turn OFF the ignition for 30 seconds.
3. Start the engine and let idle for 30 seconds.
4. Monitor the Diagnostic Trouble Code (DTC) Information with the scan tool.
Does the DTC fail this ignition? 

Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition. 2. Disconnect the mass air flow (MAF) sensor harness connector.
3. Start the engine and let idle for 30 seconds.
4. Monitor the DTC Information with the scan tool.
Does DTC P0100 (Symptom Code B) set, but not
DTC P0100 (Symptom Code C)? 

Go to Step 4 Go to Step 5

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-105
Step Action Value(s) Yes No
5 1. Remove the fuel hose that connects to the fuel
injection pump suction side.
2. Remove the fuel pipe connector that connects to the fuel injection pump suction side.
3. Inspect the eye bolt for any type of restriction or collapsed gauze filter.
Notice: If any type of restriction found, check for a
condition that causes contaminated fuel, such as the
customer is using an aftermarket fuel filter or
extended maintenance interval.Also inspect fuel
waxing or icing that is caused by an incorrect fuel
type used in winter season or water intrusion in the
fuel system.
4. Repair or replace as necessary.
Did you find and correct the condition? 

Go to Step 9 Go to Step 6
6 1. Disconnect the fuel hose that connects to the fuel injection pump suction side. In order to
measure the discharged fuel amount, put the
hose into a bottle or a container.
2. Pump the priming pump on the fuel filter.
Notice: If there is a leak on the suction side of the
fuel system, the fuel from the disconnected hose will
not flow out sufficiently and fuel leakage may occur.
Also if there is a restriction on the suction side of the
fuel system, the fuel from the disconnected hose will
not flow out sufficiently that is most likely caused by
clogged fuel filter or kinked fuel hose or pipe.
3. Draw fuel from the fuel tank at the fuel line (as close to the fuel tank as possible) going to the
fuel pickup tube to verify a clean stream of fuel
comes out (use the hand-held vacuum pump 5-
8840-0279-0/J-23738-A with a clear hose or
equivalent). This will ensure the fuel pickup tube
is not cracked drawing air into the fuel line.
4. Repair any fuel system leaks and restrictions as necessary.
Did you find and correct the condition? 

Go to Step 9 Go to Step 7

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ISUZU KB P190 2007