2007 ISUZU KB P190 engine

6E-138 Engine Control System (4JH1)
Step Action Value(s) Yes No
16 1. Reconnect all previously disconnected fuse,
relay or harness connector(s).
2. Clear the DTCs with the scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine and warm up (allow engine coolant temperature to reach at least 65 °C
[149 °F]).
5. Monitor the DTC Information with the scan tool.
Did the DTC fail this ignition? 

Go to Step 2 Go to Step 17
17 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


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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-139
DTC P0380 (Symptom Code 8) (Flash Code 66)
Circuit Description
The engine control module (ECM) controls the glo
w
relay which supplies power to the glow plugs based on
engine coolant temperature. In the after glow phase, the
glow indicator light is not illuminated but glow plugs
remain active for a certain period. If the ECM detects a
short to battery or ignition voltage on the glow rela
y
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 relay control circuit for longer than 1
second when the relay 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.
Notice:
• The glow relay is commanded OFF with ignition
ON and engine OFF when the engine coolant
temperature is reached at 30°C (86°F).
• The glow relay is commanded OFF with engine
run when the engine coolant temperature is
reached at 60°C (140°F).

DTC P0380 (Symptom Code 8) (Flash Code 66)
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 Relay test with the scan tool.
4. Command the Glow Relay ON with the scan tool.
Does the glow relay click when commanded ON with
the scan tool? 

Go to Diagnostic Aids Go to Step 3
3 1. Turn OFF the ignition. 2. Replace the glow relay with the starter relay or replace with a known good relay.
3. Turn ON the ignition, with the engine OFF.
4. Command the Glow Relay ON with the scan tool.
Does the glow relay click when commanded ON with
the scan tool? 

Go to Step 5 Go to Step 4
4 1. Test the control circuit of the glow relay between the engine control module (ECM) (pin 94 of C-57
connector) and the glow relay (pin 3 of X-5
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 glow relay. Did you complete the replacement? 

Go to Step 7 
6 Important: Replacement ECM must be
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this section.
Did you complete the replacement? 

Go to Step 7 

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ISUZU KB P190 2007

6E-140 Engine Control System (4JH1)
Step Action Value(s) Yes No
7 1. Reconnect all previously disconnected relay or
harness connector(s).
2. Clear the DTCs with the scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Cool down the engine as necessary (allow engine coolant temperature to cool down at least
50 °C [122 °F]).
5. Start the engine.
6. Monitor the DTC Information with the scan tool.
Did the DTC fail this ignition? 

Go to Step 2 Go to Step 8
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


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TO MODEL INDEX
ISUZU KB P190 2007

Engine Control System (4JH1) 6E-141
DTC P0381 (Symptom Code 4) (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 an open circuit or
short to ground 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 low voltage condition on
the glow indicator lamp control circuit for longe
r
than 3 seconds when the lamp is commanded
OFF.
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).

DTC P0381 (Symptom Code 4) (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 Step 3 Go to Step 4
3 Command the Glow Indicator OFF with the scan tool.
Does the glow indicator lamp OFF? 

Go to Step 17 Go to Step 10
4 1. Turn OFF the ignition. 2. Inspect the Meter (15A) fuse (C-14) in the cabin fuse block.
Is the Meter (15A) fuse (C-14) open? 

Go to Step 5 Go to Step 6
5 Replace the Meter (15A) fuse (C-14). If the fuse continues to open, repair the short to ground on one
of the circuits that fed by the Meter (15A) fuse (C-14)
or replace the shorted attached component fed by
the Meter (15A) fuse (C-14).
Did you complete the repair? 

Go to Step 19 

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ISUZU KB P190 2007

6E-142 Engine Control System (4JH1)
Step Action Value(s) Yes No
6 1. Turn OFF the ignition.
2. Disconnect the engine control module (ECM) harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Connect a 3-amp fused jumper wire between the glow indicator lamp control circuit of the ECM
harness connector (pin 43 of C-56 connector)
and a known good ground.
Does the glow indicator lamp illuminate? 

Go to Step 11 Go to Step 7
7 1. Turn OFF the ignition. 2. Remove the instrument panel cluster (IPC).
3. Remove the glow indicator bulb from the IPC (meter assembly).
Is the glow indicator bulb burned out? 

Go to Step 15 Go to Step 8
8 1. Disconnect the IPC harness B-24 connector. 2. Connect a test lamp between the voltage feed circuit of the glow indicator lamp (pin 30 of B-24
connector) and a known good ground.
3. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate? 

Go to Step 9 Go to Step 12
9 1. Turn OFF the ignition. 2. Reconnect the ECM harness connector.
3. Connect a test lamp between the voltage feed circuit and control circuit of the glow indicator
lamp (pins 6 and 30 of B-24 connector).
4. Turn ON the ignition, with the engine OFF.
5. Perform the Glow Indicator test with the scan tool.
6. Command the Glow Indicator ON with the scan tool.
Does the test lamp turn ON when commanded ON
with the scan tool? 

Go to Step 14 Go to Step 13
10 1. Test the control circuit of the glow indicator lamp between the ECM (pin 43 of C-56 connector) and
the IPC (pin 6 of B-24 connector) for a short to
ground.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 19 Go to Step 18
11 1. Turn OFF the ignition. 2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor connection on the glow indicator lamp control
circuit at the harness connector of the ECM (pin
43 of C-56 connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 19 Go to Step 18
12 Repair the open circuit or high resistance on the voltage feed circuit of the glow indicator lamp
between the IPC (pin 30 of B-24 connector) and
Meter (15A) fuse (C-14).
Did you complete the repair? 

Go to Step 19 
13 1. Repair the open circuit or high resistance on the
control circuit of the glow indicator lamp between
the ECM (pin 43 of C-56 connector) and the IPC
(pin 6 of B-24 connector).
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 19 

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-143
Step Action Value(s) Yes No
14 1. Turn OFF the ignition.
2. Inspect for an intermittent and for poor connections on the glow indicator lamp circuits at
the IPC (pins 6 and 30 of B-24 connector).
3. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 19 Go to Step 16
15 Replace the glow indicator bulb. Did you complete the replacement? 

Go to Step 19 
16 Repair or replace the IPC (meter assembly).
Did you complete the repair or replacement? 

Go to Step 19 
17 1. Turn OFF the ignition for 30 seconds.
2. Turn ON the ignition for 30 seconds, with the engine OFF.
3. Monitor the DTC Information with the scan tool.
Does the DTC fail this ignition? 

Go to Step 18 Go to Diagnostic
Aids
18 Important: Replacement ECM must be
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this section.
Did you complete the replacement? 

Go to Step 19 
19 1. Reconnect all previously disconnected fuse or
harness connector(s).
2. Clear the DTCs with the scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Monitor the DTC Information with the scan tool.
Did the DTC fail this ignition? 

Go to Step 2 Go to Step 20
20 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


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TO MODEL INDEX
ISUZU KB P190 2007

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

Engine Control System (4JH1) 6E-145
Step Action Value(s) Yes No
4 1. Test the control circuit of the glow indicator lamp
between the engine control module (ECM) (pin
43 of C-56 connector) and the IPC (pin 6 of B-24
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 Repair or replace the IPC (meter assembly). Did you complete the repair or replacement? 

Go to Step 7 
6 Important: Replacement ECM must be
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this 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. Cool down the engine as necessary (allow engine coolant temperature to cool down at least
25 °C [77 °F]).
5. Turn ON the ignition, with the engine OFF.
6. Monitor the DTC Information with the scan tool.
Did the DTC fail this ignition? 

Go to Step 2 Go to Step 8
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


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007