2007 ISUZU KB P190 DTC CHECK

6E-144 Engine Control System (4JH1)
DTC P0381 (Symptom Code 8) (Flash Code 67)
Circuit Description
The glow indicator lamp is located on the instrument
panel cluster (IPC). The glow control system is operated
when the engine coolant temperature is low, which
allows easier engine starting. If the ignition switch is
turned ON when the engine coolant temperature is low,
the engine control module (ECM) illuminates the glo
w
indicator lamp and turns ON the glow plugs. After a
fixed time passes, the ECM turns OFF the glo
w
indicator lamp and the glow plugs. The ECM monitors
the glow indicator lamp control circuit for conditions that
are incorrect for the commanded state of the glo
w
indicator lamp. If the ECM detects a short to battery or
ignition voltage on the glow indicator control circuit, this
DTC will set.
Condition for Running the DTC • The ignition switch is ON.
Condition for Setting the DTC
• The ECM detects that the high voltage condition
on the glow indicator lamp control circuit for longe
r
than 1 second when the lamp is commanded ON.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
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 glow indicator lamp is commanded OFF with
the ignition ON and engine OFF when the engine
coolant temperature is reached at 30°C (86°F).
Test Description
The number below refers to the step number on the
diagnostic table.
3. If the control circuit of the glow indicator lamp
between the ECM and the IPC is normal, the control
circuit voltage low DTC P0381 (Symptom Code 4) will
set.

DTC P0381 (Symptom Code 8) (Flash Code 67)
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 ON the ignition, with the engine OFF.
3. Perform the Glow Indicator test with the scan tool.
4. Command the Glow Indicator ON with the scan tool.
Does the glow indicator lamp turn ON when
commanded ON with the scan tool? 

Go to Diagnostic Aids Go to Step 3
3 1. Turn OFF the ignition. 2. Remove the instrument panel cluster (IPC) in order to disconnect the IPC harness B-24
connector.
3. Disconnect the IPC harness B-24 connector.
4. Turn ON the ignition for 30 seconds, with the engine OFF.
5. Monitor the Diagnostic Trouble Code (DTC) Information with the scan tool.
Does DTC P0381 (Symptom Code 4) set, but not
DTC P0381 (Symptom Code 8)? 

Go to Step 5 Go to Step 4

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ISUZU KB P190 2007

6E-146 Engine Control System (4JH1)
DTC P0400 (Symptom Code 3) (Flash Code 32)
Circuit Description
The engine control module (ECM) controls the exhaust
gas recirculation (EGR) flow amount based on the
engine speed, engine coolant temperature, intake ai
r
temperature, barometric pressure and fuel injection
quantity. The ECM controls the EGR valve b
y
controlling the EGR solenoid valve. The mass air flo
w
(MAF) sensor monitors EGR gas flow amount. An
expected MAF amount should be detected while the
engine running. If the ECM detects the actual MAF
amount is lower than desired MAF amount, this DTC
will set. This indicates excessive amount of EGR gas
flow.
Condition for Running the DTC
• The ignition switch is ON.
• The engine is running.
• The barometric pressure (BARO) is between 850
hPa and 1100 hPa.
• The intake air temperature (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).
Condition for Setting the DTC

• The ECM detects that the MAF amount is 150
mg/strk lower than the desired MAF for 60
seconds. This indicates excessive amount of EGR
flow.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicator
lamp (MIL) when the diagnostic runs and fails.
• The ECM limits fuel injection quantity.
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.
• A sticking or intermittently sticking the EGR valve
will cause this DTC to set.
• Misrouted vacuum hoses will cause this DTC to
set.

DTC P0400 (Symptom Code 3) (Flash Code 32)
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.
Is DTC P0100 (Symptom Code 7, 9, B or C) or
P0400 (Symptom Code 4 or 8) set? 

Go to Applicable DTC Go to Step 3
3 1. Install the scan tool. 2. Turn OFF the ignition for 30 seconds.
3. Start the engine and warm up (allow engine coolant temperature to reach at least 60°C
[140°F]).
4. Perform the EGR Solenoid Valve test with the scan tool.
5. Command the EGR Solenoid Valve ON and OFF with the scan tool while observing the Mass Air
Flow (MAF) Sensor parameter.
Does the MAF Sensor parameter decrease by at
least 200 mg/strk within 2 seconds when the EGR
Solenoid Valve is commanded ON? 

Go to Diagnostic Aids Go to Step 4

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-149
DTC P0400 (Symptom Code 4) (Flash Code 32)
Circuit Description
The engine control module (ECM) controls the exhaust
gas recirculation (EGR) flow amount based on the
engine speed, engine coolant temperature, intake ai
r
temperature, barometric pressure and fuel injection
quantity. The ECM controls the EGR valve b
y
controlling the EGR solenoid valve. The mass air flo
w
(MAF) sensor monitors EGR gas flow amount. An
expected MAF amount should be detected while the
engine running. If the ECM detects that an open circuit
or short to ground on the EGR solenoid valve control
circuit, this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.
Condition for Setting the DTC • The ECM detects that the low voltage condition on
the EGR solenoid valve control circuit for longe
r
than 3 seconds when the solenoid valve is
commanded OFF.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
• The ECM limits fuel injection quantity.
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.

DTC P0400 (Symptom Code 4) (Flash Code 32)
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. 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 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 15 
5 1. Turn OFF the ignition.
2. Disconnect the EGR control solenoid valve harness connector.
3. Connect a test lamp between the voltage feed circuit of the EGR control solenoid valve harness
(pin 1 of C-115 connector) and a known good
ground.
4. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate? 

Go to Step 6 Go to Step 8

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ISUZU KB P190 2007

6E-152 Engine Control System (4JH1)
DTC P0400 (Symptom Code 5) (Flash Code 32)
Circuit Description
The engine control module (ECM) controls the exhaust
gas recirculation (EGR) flow amount based on the
engine speed, engine coolant temperature, intake ai
r
temperature, barometric pressure and fuel injection
quantity. The ECM controls the EGR valve b
y
controlling the EGR solenoid valve. The mass air flo
w
(MAF) sensor monitors EGR gas flow amount. An
expected MAF amount should be detected while the
engine running. If the ECM detects the actual MAF
amount is higher than desired MAF amount, this DTC
will set. This indicates insufficient amount of EGR gas
flow.
Condition for Running the DTC
• The ignition switch is ON.
• The engine is running.
• The barometric pressure (BARO) is between 850
hPa and 1100 hPa.
• The intake air temperature (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).
Condition for Setting the DTC
• The ECM detects that the MAF amount is 150
mg/strk higher than the desired MAF for 60
seconds. This indicates insufficient amount o
f
EGR flow.
Action Taken When the DTC Sets

• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
• The ECM limits fuel injection quantity.
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.
• A sticking or intermittently sticking the EGR valve
will cause this DTC to set.
• Misrouted vacuum hoses will cause this DTC to
set.
•
A vacuum pump problem will cause this DTC to
set.

DTC P0400 (Symptom Code 5) (Flash Code 32)
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.
Is DTC P0100 (Symptom Code 7, 9, B or C) or
P0400 (Symptom Code 4 or 8) set? 

Go to Applicable DTC Go to Step 3
3 1. Install the scan tool. 2. Turn OFF the ignition for 30 seconds.
3. Start the engine and warm up (allow engine coolant temperature to reach at least 60°C
[140°F]).
4. Perform the EGR Solenoid Valve test with the scan tool.
5. Command the EGR Solenoid Valve ON and OFF with the scan tool while observing the Mass Air
Flow (MAF) Sensor parameter.
Does the MAF Sensor parameter decrease by at
least 200 mg/strk within 2 seconds when the EGR
Solenoid Valve is commanded ON? 

Go to Diagnostic Aids Go to Step 4

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-155
DTC P0400 (Symptom Code 8) (Flash Code 32)
Circuit Description
The engine control module (ECM) controls the exhaust
gas recirculation (EGR) flow amount based on the
engine speed, engine coolant temperature, intake ai
r
temperature, barometric pressure and fuel injection
quantity. The ECM controls the EGR valve by
controlling the EGR solenoid valve. The mass air flo
w
(MAF) sensor monitors EGR gas flow amount. An
expected MAF amount should be detected while the
engine running. If the ECM detects that detects a short
to battery or ignition voltage on the EGR solenoid valve
control circuit, this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.
Condition for Setting the DTC • The ECM detects that the high voltage condition
on the EGR solenoid valve control circuit for longe
r
than 3 seconds when the solenoid valve is
commanded ON.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
• The ECM limits fuel injection quantity.
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.
Test Description
The number below refers to the step number on the
diagnostic table.
3. If the control circuit of the EGR solenoid valve
between the ECM and the solenoid valve is normal, the
control circuit voltage low DTC P0400 (Symptom Code
4) will set.

DTC P0400 (Symptom Code 8) (Flash Code 32)
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 warm up (allow engine coolant temperature to reach at least 60°C
[140°F]).
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 EGR control solenoid valve harness connector.
3. Start the engine.
4. Monitor the DTC Information with the scan tool.
Does the DTC P0400 (Symptom Code 4) set, but not
DTC P0400 (Symptom Code 8)? 

Go to Step 5 Go to Step 4
4 1. Test the control circuit between the engine control module (ECM) (pin 97 of C-57 connector)
and the EGR solenoid valve (pin 2 of C-115
connector) for a short to battery or ignition
voltage.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 7 Go to Step 6
5 Replace the EGR solenoid valve. Refer to EGR Solenoid Valve Replacement in this section.
Did you complete the replacement? 

Go to Step 7 

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-157
DTC P0500 (Symptom Code 1, A) (Flash Code 24)
Circuit Description
The vehicle speed sensor (VSS) is used by the engine
control module (ECM) and speedometer, which
generates a speed signal from the transmission output
shaft. The VSS has the following circuits.
• Ignition voltage feed circuit
• VSS signal circuit
• VSS low reference circuit
The VSS uses a hall effect element. It interacts with the
magnetic field created by the rotating magnet and
outputs square wave pulse signal. The 12 volts
operating supply from the Meter fuse (except 2W D with
A/T) or Back Up fuse (2W D with A/T). The ECM
calculates the vehicle speed by the VSS. If the vehicle
is 2W D with automatic transmission, VSS signals are
sent from the transmission control module (TCM). If the
ECM detects VSS signals are generated with high
frequencies, this DTC will set.
Condition for Running the DTC
• The ignition switch is ON.
Condition for Setting the DTC
• The ECM detects that the vehicle speed is highe
r
than 200 km/h (125 MPH) for 5 seconds.
(Symptom Code 1)

•
The ECM detects that the vehicle speed senso
r
signal frequency is too high for 0.6 seconds.
(Symptom Code A)
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 vehicle speed substitution of 5
km/h (3 MPH) for engine control.
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
• Electrical or magnetic interference may affect
intermittent condition.
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.

DTC P0500 (Symptom Code 1, A) (Flash Code 24)
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or Engine Control Module (ECM)
Connector End Views

Chart for 2WD with A/T
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. Inspect all of the circuits going to the automatic transmission (A/T) vehicle speed sensor (VSS)
for the following: • Routed too closely to fuel injection solenoid
wiring or components
• Routed too closely to after-market add-on
electrical equipment
• Routed too closely to solenoids, relays, and
motors
2. If you find incorrect routing, correct the harness routing.
Did you find and correct the condition? 

Go to Step 7 Go to Step 3
3 1. Turn OFF the ignition. 2. Disconnect the A/T VSS harness connector.
3. Inspect for an intermittent and for poor connections at the harness connector of the A/T
VSS (pins 1, 2 and 3 of E-30 connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 7 Go to Step 4

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ISUZU KB P190 2007

6E-158 Engine Control System (4JH1)
Step Action Value(s) Yes No
4 1. Turn OFF the ignition.
2. Disconnect the engine control module (ECM) harness connector.
3. Inspect for an intermittent and for a poor connection on A/T VSS circuit at the harness
connector of the ECM (pin 68 of C-56 connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 7 Go to Step 5
5 1. Remove the A/T VSS. Refer to A/T Speed Sensor Replacement in automatic transmission
section.
2. Visually inspect the A/T VSS for the following conditions: • Physical damage
• Being loose
• Improper installation
3. The following conditions may cause this DTC to set: • Electromagnetic interference in the A/T
VSS circuits
4. Repair or replace as necessary.
Did you find and correct the condition? 

Go to Step 7 Go to Step 6
6 Replace the A/T VSS. Refer to A/T Speed Sensor Replacement in automatic transmission section
Did you complete the replacement? 

Go to Step 7 
7 1. Reconnect all previously disconnected harness
connector(s).
2. Clear the DTCs with the scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Drive the vehicle.
5. Observe the Vehicle Speed parameter with the scan tool.
Does the Vehicle Speed parameter indicate correct
vehicle speed? 

Go to Step 8 Go to Step 2
8 Observe the DTC Information with the scan tool. Are there any DTCs that you have not diagnosed?  Go to Diagnostic
Trouble Code (DTC) List System OK

Chart for except 2WD with A/T
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. Inspect all of the circuits going to the vehicle speed sensor (VSS) for the following: • Routed too closely to fuel injection solenoid
wiring or components
• Routed too closely to after-market add-on
electrical equipment
• Routed too closely to solenoids, relays, and
motors
2. If you find incorrect routing, correct the harness routing.
Did you find and correct the condition? 

Go to Step 7 Go to Step 3

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ISUZU KB P190 2007

6E-160 Engine Control System (4JH1)
DTC P0500 (Symptom Code B) (Flash Code 24)
Circuit Description
The vehicle speed sensor (VSS) is used by the engine
control module (ECM) and speedometer, which
generates a speed signal from the transmission output
shaft. The VSS has the following circuits.
• Ignition voltage feed circuit
• VSS signal circuit
• VSS low reference circuit
The VSS uses a hall effect element. It interacts with the
magnetic field created by the rotating magnet and
outputs square wave pulse signal. The 12 volts
operating supply from the Meter fuse (except 2W D with
A/T) or Back Up fuse (2W D with A/T). The ECM
calculates the vehicle speed by the VSS. If the vehicle
is 2W D with automatic transmission, VSS signals are
sent from the transmission control module (TCM). If the
ECM detects VSS signals are not generated, this DTC
will set.
Condition for Running the DTC
• The ignition switch is ON.
• The engine speed is higher than 3600 RPM.
• The fuel injection quantity is more than 41 mg/strk.
Condition for Setting the DTC
• The ECM detects that the vehicle speed is lowe
r
than 1.5 km/h (1 MPH) for 60 seconds.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicato
r
lamp (MIL) when the diagnostic runs and fails.
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
• Electrical or magnetic interference may affect
intermittent condition.
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.

DTC P0500 (Symptom Code B) (Flash Code 24)
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or Engine Control Module (ECM)
Connector End Views

Chart for 2WD with A/T
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. Turn ON the ignition, with the engine OFF.
4. Select the “JR405E Automatic Transmission” in the system selection menu.
5. Monitor the Read Diagnostic Trouble Code (DTC) Info As Stored By ECU with the scan tool.
Does the transmission control module (TCM) DTC
P0722 set? 

Go to Applicable
DTC in Automatic Transmission Section Go to Step 3
3 1. Drive the vehicle. 2. Select the data display function of engine control module (ECM).
3. Observe the Vehicle Speed parameter with the scan tool.
Does the Vehicle Speed parameter indicate correct
vehicle speed? 

Go to Diagnostic Aids Go to Step 4
4 1. Turn OFF the ignition. 2. Disconnect the TCM harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Intermittently jump the VSS signal output circuit (pin A-10 of C-94 connector) with a test lamp that
is connected to a known good ground while
monitoring the Vehicle Speed parameter with the
scan tool.
Does the scan tool indicate any vehicle speed when
the circuit is intermittently pulled to ground? 

Go to Step 8 Go to Step 5

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ISUZU KB P190 2007