2007 ISUZU KB P190 relay

Engine Control System (4JH1) 6E-59
DTC
(Symptom Code) Flash
Code MIL
Status DTC Name on
scan tool Condition for
Running the DTC Condition for
Setting the DTC Possible Cause
P0606
(A) 28 ON Control Module
Internal
Performance

•
The ECM detects
that the internal
CPU does not
react.
•
Faulty ECM.
P0606
(B) 28 ON Control Module
Internal
Performance •
The accelerator
pedal position is
less than 1%.
• The desired fuel
injection quantity is
0 mg/strk.
•
The ECM detects
that the engine
speed is higher
than 2000 RPM. •
Faulty ECM.
P0645
(4) 46 ON Air Conditioning
(A/C) Clutch Relay
Control Circuit Low
Voltage •
The ignition switch
is ON.
• The A/C
compressor relay is
once commanded
ON. •
The ECM detects
that the low voltage
condition on the
A/C compressor
relay control circuit
for longer than 3
seconds when the
relay is commanded
OFF.
•
ECM (10A) fuse (EB1) open.
• A/C compressor relay ignition
voltage feed circuit on coil side is
open circuit or high resistance.
• A/C compressor relay control
circuit is open circuit, high
resistance or short to ground.
• A/C compressor relay is poor
installation.
• Faulty A/C compressor relay.
• Faulty ECM.

P0645 (8) 46 ON Air Conditioning
(A/C) Clutch Relay
Control Circuit
High Voltage •
The ignition switch
is ON.
• The A/C
compressor relay is
once commanded
ON. •
The ECM detects
that the high
voltage condition on
the A/C compressor
relay control circuit
for longer than 3
seconds when the
relay is commanded
ON.
•
A/C compressor relay control
circuit is short to battery or
ignition voltage circuit.
• Faulty A/C compressor relay.
• Faulty ECM.

P0703 (A) 25 ON Brake Switch
Circuit •
The ignition switch
is ON.
• The engine speed
is higher than 665
RPM.
• The vehicle speed
is higher than 0
km/h (0 MPH).
•
The ECM detects
that the brake pedal
1 switch is ON
(Applied) when the
brake pedal 2
switch is OFF
(Released) for
longer than 30
seconds within the
enabling conditions
ever since ignition
switch is ON. •
Stop (15A) fuse (C-15) open.
• ECM (10A) fuse (EB-4) open.
• Brake pedal 1 switch battery
voltage feed circuit is open
circuit or high resistance.
• Brake pedal 1 switch signal
circuit is open circuit, high
resistance, short to battery or
ignition voltage.
• Brake pedal 2 switch ignition
voltage feed circuit is open
circuit or high resistance.
• Brake pedal 2 switch signal
circuit is open circuit, high
resistance, short to battery or
ignition voltage.
• Misadjusted brake pedal switch.
• Brake pedal switch is poor
connection.
• Faulty brake pedal switch.
• Faulty ECM.


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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-63
DTC
(Symptom Code) Flash
Code MIL
Status DTC Name on
scan tool Condition for
Running the DTC Condition for
Setting the DTC Possible Cause
P1605
(D) 55 ON Control Module
Internal
Performance  •
The ECM detects
reading or writing
from the EEPROM
data is failed during
initialization.
•
Faulty ECM.
P1605
(E) 55 ON Control Module
Internal
Performance
 •
The ECM detects
total sum of
EEPROM data is
not equal to
registered value
during initialization.
•
Faulty ECM.
P1610
(A) *1 56 ON Immobilizer
Function Not
Programmed  •
The ECM detects
immobilizer security
code and secret key
is not programmed.
•
Immobilizer function is not
programmed into the ECM.
• Faulty ECM.

P1611 (A) *1 56 ON W rong Security
Code Entered
 •
The ECM detects
wrong immobilizer
security code is
programmed.
•
Programming ECM with wrong
security code.
• Faulty ECM.

P1612 (A) *1 56 ON Immobilizer W rong
Signal
 •
The ECM receives
wrong immobilizer
response signal
from the ICU.
•
Keyword 2000 communication
line is open circuit, high
resistance, short to ground, short
to battery or ignition voltage.
• Electrical interference.
• Magnetic interference.
• Faulty ECM.
• Faulty ICU.

P1613 (A) *1 56 ON Immobilizer No
Signal
 •
The ECM does not
receive the
immobilizer
response signal
from the ICU.
•
Keyword 2000 communication
line is open circuit, high
resistance, short to ground, short
to battery or ignition voltage.
• Electrical interference.
• Magnetic interference.
• Faulty transponder key.
• Faulty antenna coil.
• Faulty ECM.
• Faulty ICU.

P1614 (A) *1 56 ON W rong
Transponder Key
 •
The ICU receives
wrong immobilizer
response signal
from the
transponder key.
•
Faulty transponder key.
• Faulty ICU.

P1625 (A) 76 OFF ECM Main Relay
Circuit
 •
The ECM detects
that the ECM main
relay is turned OFF
before commanded
turned OFF.
•
ECM main relay control circuit is
intermittently open circuit or high
resistance.
• ECM battery voltage feed circuit
is intermittently open or high
resistance.
• Faulty ECM main relay.

*1: This DTC may be set if the ECM with wrong specification is installed.

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ISUZU KB P190 2007

6E-64 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
P1625
(B) 76 OFF ECM Main Relay
Circuit •
The ignition switch
is OFF. •
The ECM detects
that the ECM main
relay is turned ON
for longer than 2
seconds. •
ECM main relay control circuit is
short to ground.
• ECM battery voltage circuit is
short to battery.
• Faulty ECM main relay.
• Faulty ECM.

P1630 (A) 51 ON Injection Pump
Fuel Metering
Control
 •
The ECM detects
that the PCU
monitored fuel
injection solenoid
valve control
current is too high.
•
Faulty fuel injection pump.
• Faulty PCU.

P1630 (B) 51 ON Injection Pump
Fuel Metering
Control
 •
The ECM detects
that the PCU
continuously flow
the control current
to the fuel injection
solenoid valve.
•
Faulty fuel injection pump.
• Faulty PCU.

P1650 (A) 44 ON CAN Device
Offline
 •
The ECM detects
that the PCU
receives from the
CAN controller
reset or Bus Offline.
•
CAN high circuit is open circuit,
high resistance, short to ground,
short to battery or ignition
voltage.
• CAN low circuit is open circuit,
high resistance, short to ground,
short to battery or ignition
voltage.
• Electrical interference.
• Magnetic interference.
• Faulty PCU.
• Faulty ECM.

P1650 (B) 44 ON CAN Device Hang-
up
 •
The ECM detects
internal CAN
controller does not
react.
•
Faulty ECM.


P1651 (A) 45 ON CAN Malfunction
 •
The ECM detects
that the PCU does
not receive the CAN
messages from the
ECM.
•
CAN high circuit is open circuit,
high resistance, short to ground,
short to battery or ignition
voltage.
• CAN low circuit is open circuit,
high resistance, short to ground,
short to battery or ignition
voltage.
• Electrical interference.
• Magnetic interference.
• Faulty PCU.
• Faulty ECM.


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ISUZU KB P190 2007

6E-136 Engine Control System (4JH1)
DTC P0380 (Symptom Code 4) (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 an
open circuit or short to ground on the glow relay 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 relay control circuit for longer than 3
seconds when the relay 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.
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 4) (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 12 Go to Step 4
4 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 5 Go to Step 6
5 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 16 
6 1. Turn OFF the ignition.
2. Remove the glow relay.
3. Connect a test lamp between the voltage feed circuit of the glow relay coil side (pin 2 of X-5
connector) and a known good ground.
4. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate? 

Go to Step 7 Go to Step 9

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-137
Step Action Value(s) Yes No
7 1. Turn OFF the ignition.
2. Connect a test lamp between the control circuit of the glow relay (pin 3 of X-5 connector) and
battery voltage.
3. Turn ON the ignition, with the engine OFF.
Does the test lamp continuously illuminate (the test
lamp blinks then goes out normally if the engine
coolant temperature lower than 30°C [86°F])? 

Go to Step 10 Go to Step 8
8 1. Keep the test lamp with connected. 2. Command the Glow Relay ON with the scan tool.
Does the test lamp illuminate when commanded ON
with the scan tool? 

Go to Step 12 Go to Step 11
9 Repair the voltage feed circuit between the ECM (10A) fuse (EB-4) and the glow relay (pin 2 of X-5
connector) for an open circuit or high resistance.
Did you complete the repair? 

Go to Step 16 
10 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 ground.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 16 Go to Step 15
11 1. Test the control circuit of the glow relay between the ECM (pin 94 of C-57 connector) and the glow
relay (pin 3 of X-5 connector) for an open circuit
or high resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 16 Go to Step 13
12 1. Turn OFF the ignition. 2. Inspect for an intermittent and for poor connections on the glow relay terminals (pins 2
and 3 of X-5 connector).
3. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 16 Go to Step 14
13 1. Turn OFF the ignition. 2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor connection on the glow relay control circuit at the
harness connector of the ECM (pin 94 of C-57
connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 16 Go to Step 15
14 Replace the glow relay. Did you complete the replacement? 

Go to Step 16 
15 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 16 

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ISUZU KB P190 2007

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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ISUZU KB P190 2007