2007 ISUZU KB P190 Circuit

Engine Control System (4JH1) 6E-45
Step Action Value(s) Yes No
8 Important: An open in a ground circuit at the ECM
will not cause a loss of communication.
1. Check ECM ground for corrosion and tightness.
2. Clean or tighten grounds as necessary.
Did you find and correct the condition? 

Go to Step 17 Go to Step 9
9 1. Turn OFF the ignition. 2. Reconnect the ECM harness connector if previously disconnected.
3. Turn ON the ignition, with the engine OFF.
4. Replace the ECM main relay with the tail relay or replace with a known good relay.
5. Attempt to establish scan tool communications with the ECM.
Does the ECM communicate with the scan tool? 

Go to Step 15 Go to Step 10
10 1. Turn OFF the ignition. 2. Remove the ECM main relay.
3. Turn ON the ignition, with the engine OFF.
4. Using a test lamp, check for battery voltage at both of the battery voltage supply circuits to the
ECM main relay (pins 2 and 5 of X-12
connector).
5. Repair the open in the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 17 Go to Step 11
11 1. Reinstall the ECM main relay. 2. Turn the ignition ON and OFF while listening or feeling for the ECM main relay click. W ait 2
seconds between transitions.
Does the ECM main relay click when the ignition is
turned ON or OFF? 

Go to Step 13 Go to Step 12
12 Repair the ECM main relay control circuit between the ECM main relay (pin 4 of X-12 connector) and
the ECM (pin 58 of C-56 connector) for the following
conditions: • An open circuit
• A short to battery or ignition voltage
• High resistance or a poor connection at
both the ECM and ECM main relay
Did you find and correct the condition? 

Go to Step 17 Go to Step 16
13 1. Check ECM main relay voltage supply circuit to the ECM between the ECM main relay (pin 1 of
X-12 connector) and the ECM (pin 3 of C-56
connector) for the following conditions: • An open circuit
• High resistance or a poor connection at the
ECM and ECM main relay
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 17 Go to Step 16
14 Repair the open in the ignition voltage circuit to the ECM.
Did you complete the repair? 

Go to Step 17 
15 Replace the ECM main relay.
Did you complete the replacement? 

Go to Step 17 
16 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 17 

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

6E-50 Engine Control System (4JH1)
Diagnostic Trouble Code (DTC) List
DTC
(Symptom Code) Flash
Code MIL
Status DTC Name on
scan tool Condition for
Running the DTC Condition for
Setting the DTC Possible Cause
P0100
(7) 65 ON Mass Air Flow
(MAF) Sensor
Circuit 5V
Reference High
Voltage •
The ignition switch
is ON.
•
The ECM detects
that the MAF sensor
5 volts reference
circuit voltage is
more than 5.2 volts
for 0.5 seconds. •
Sensor 5V reference circuit is
short to battery or ignition
voltage.
• Sensor 5V reference circuit is
short to the sensor ignition
voltage circuit.
• Faulty MAF sensor.
• Faulty ECM.

P0100 (9) 65 ON Mass Air Flow
(MAF) Sensor
Voltage 5V
Reference Circuit
Low Voltage •
The ignition switch
is ON.
•
The ECM detects
that the MAF sensor
5 volts reference
circuit voltage is
less than 4.6 volts
for 0.5 seconds. •
Sensor 5V reference circuit is
short to ground.
• Sensor 5V reference circuit is
short to the low reference circuit.
• Faulty MAF sensor.
• Faulty ECM.

P0100 (B) 65 ON Mass Air Flow
(MAF) Sensor
Circuit Low
Voltage •
The ignition switch
is ON.
• The engine is
running.
•
The ECM calculated
MAF is lower than -
18.6 kg/h for 5
seconds.
•
ECM (10A) fuse (EB1) open.
• Sensor ignition voltage feed
circuit is open circuit or high
resistance.
• Sensor 5V reference circuit is
open circuit, high resistance,
short to ground or short to the
low reference circuit.
• Sensor signal circuit is open
circuit, high resistance, short to
ground or short to the low
reference circuit.
• Poor harness connector
connection.
• Faulty MAF sensor installation.
• Faulty MAF sensor.
• Faulty ECM.

P0100 (C) 65 ON Mass Air Flow
(MAF) Sensor
Circuit High
Voltage •
The ignition switch
is ON.
• The engine is
running.
•
The ECM calculated
MAF is higher than
984 kg/h for 10
seconds.
•
Sensor signal circuit is short to
any 5V reference circuit, short to
battery or ignition voltage circuit.
• Sensor low reference circuit is
open circuit or high resistance.
• Poor harness connector
connection.
• Faulty MAF sensor.
• Faulty ECM.

P0105 (1) 34 ON Vacuum Pressure
Sensor Circuit
High Voltage •
The ignition switch
is ON. •
The ECM detects
that the vacuum
pressure sensor
signal voltage is
more than 4.4 volts
for 3 seconds. •
Sensor 5V reference circuit is
short to battery or ignition
voltage.
• Sensor signal circuit is short to
any 5V reference circuit, short to
battery or ignition voltage.
• Sensor low reference circuit is
open circuit or high resistance.
• Poor harness connector
connection.
• Faulty vacuum pressure sensor.
• Faulty ECM.


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Control System (4JH1) 6E-51
DTC
(Symptom Code) Flash
Code MIL
Status DTC Name on
scan tool Condition for
Running the DTC Condition for
Setting the DTC Possible Cause
P0105
(2) 34 ON Vacuum Pressure
Sensor Circuit Low
Voltage •
The ignition switch
is ON. •
The ECM detects
that the vacuum
pressure sensor
signal voltage is
less than 0.5 volts
for 3 seconds. •
Sensor 5V reference circuit is
open circuit or high resistance,
short to ground or short to the
low reference circuit.
• Sensor signal circuit is open
circuit, high resistance, short to
ground or short to the low
reference circuit.
• Poor harness connector
connection.
• Faulty vacuum pressure sensor.
• Faulty ECM.

P0105 (7) 34 ON Vacuum Pressure
Sensor Voltage 5V
Reference Circuit
High Voltage
•
The ignition switch
is ON. •
The ECM detects
that the vacuum
pressure sensor 5
volts reference
circuit voltage is
more than 5.2 volts
for 2.5 seconds.
•
Sensor 5V reference circuit is
short to battery or ignition
voltage.
• Faulty ECM.

P0105 (9) 34 ON Vacuum Pressure
Sensor Voltage 5V
Reference Circuit
Low Voltage
•
The ignition switch
is ON. •
The ECM detects
that the vacuum
pressure sensor 5
volts reference
circuit voltage is
less than 4.5 volts
for 2.5 seconds.
•
Sensor 5V reference circuit is
short to ground or short to low
reference circuit.
• Faulty vacuum pressure sensor.
• Faulty ECM.

P0110 (1) 23 ON Intake Air
Temperature (IAT)
Sensor Circuit
High Voltage •
The ignition switch
is ON.
•
The ECM detects
that the IAT sensor
signal voltage is
more than 4.7 volts
for 3 seconds. •
Sensor signal circuit is open
circuit, high resistance, short to
any 5V reference circuit, short to
battery or ignition voltage.
• Sensor low reference circuit is
open circuit or high resistance.
• Poor harness connector
connection.
• Faulty IAT sensor.
• Faulty ECM.

P0110 (2) 23 ON Intake Air
Temperature (IAT)
Sensor Circuit Low
Voltage
•
The ignition switch
is ON.
•
The ECM detects
that the IAT sensor
signal voltage is
less than 0.3volts
for 3 seconds.
•
Sensor signal circuit is short to
ground or short to the low
reference circuit.
• Faulty IAT sensor.
• Faulty ECM.
P0115
(1) 14 ON Engine Coolant
Temperature
(ECT) Sensor
Circuit High
Voltage •
The ignition switch
is ON.
•
The ECM detects
that the ECT sensor
signal voltage is
more than 4.7 volts
for 3 seconds. •
Sensor signal circuit is open
circuit, high resistance, short to
any 5V reference circuit, short to
battery or ignition voltage.
• Sensor low reference circuit is
open circuit or high resistance.
• Poor harness connector
connection.
• Faulty ECT sensor.
• Faulty ECM.

P0115 (2) 14 ON Engine Coolant
Temperature
(ECT) Sensor
Circuit Low
Voltage
•
The ignition switch
is ON.
•
The ECM detects
that the ECT sensor
signal voltage is
less than 0.3volts
for 3 seconds. •
Sensor signal circuit is short to
ground or short to the low
reference circuit.
• Faulty ECT sensor.
• Faulty ECM.


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

6E-52 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
P0180
(B) 15 ON Fuel Temperature
Sensor Circuit •
Ignition switch is
ON.
•
The PCU internal
FT sensor output is
lower than -40°C (-
40°F) for 3 seconds
or higher than
150°C (302°F) for 3
seconds.
•
Faulty PCU.

P0215 (A) 52 ON at
next
ignition cycle Engine Shutoff
(ESO) Solenoid
Control Circuit •
The ignition switch
is OFF.
• The engine speed
is lower than 1500
RPM.
• The vehicle speed
is lower than 1.5
km/h (1 MPH).
•
After the condition
for running the DTC
for 2 seconds, the
engine speed is
higher than 200
RPM when the ESO
solenoid valve is
commanded shutoff
from the PCU.
•
Faulty fuel injection pump.

P0215 (B) 52 ON Engine Shutoff
(ESO) Solenoid
Control Circuit •
The ignition switch
is ON. •
The PCU detects
high voltage
condition on the
ESO solenoid valve
control circuit for
longer than 1
second when the
ECM does not
command shutoff.
•
ESO solenoid valve control
circuit is short to battery or
ignition voltage.
• Faulty PCU.
• Faulty ECM.

P0215 (C) 52 ON Engine Shutoff
(ESO) Solenoid
Control Circuit •
The ignition switch
is OFF.
• The engine speed
is lower than 1500
RPM.
• The vehicle speed
is lower than 1.5
km/h (1 MPH).
•
The engine speed
is higher than 200
RPM within 2
seconds after the
condition for
running the DTC
are met.
•
ESO solenoid valve control
circuit is open circuit, high
resistance or short to ground.
• Faulty PCU.
• Faulty ECM.

P0215 (D) 52 ON Engine Shutoff
(ESO) Solenoid
Control Circuit
•
The ignition switch
is OFF. •
The ECM detects
internal CAN
controller does not
Bus OFF mode.
•
Faulty ECM.


P0216 (A) 54 ON Injection Timing
Control Circuit •
The engine speed
is higher than 700
RPM.
• The fuel injection
quantity is higher
than 4 mg/strk.
•
The PCU monitored
actual fuel injection
timing is advanced
more than desired
by 3°CA for longer
than 12 seconds or
retarded more than
desired by 6°CA for
longer than 12
seconds.
•
Excessive air in the fuel system.
• Loss fuel.
• Fuel suction side looseness,
kinks or blocked.
• Faulty or clogged fuel filter.
• Contaminated fuel.
• Faulty timing device.
• Faulty fuel injection pump CMP
sensor.


P0216 (B) 54 ON Injection Timing
Control Circuit •
The engine speed
is higher than 2014
RPM.
•
The PCU monitored
actual fuel injection
timing is oscillated
higher than desired
by 5.2°CA.
•
Excessive air in the fuel system.
• Loss fuel.
• Fuel suction side looseness,
kinks or blocked.
• Faulty or clogged fuel filter.
• Contaminated fuel.
• Faulty timing device.
• Faulty fuel injection pump CMP
sensor.


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

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.


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

6E-54 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
P0243
(8) 64 ON Turbocharger
W aste gate
Solenoid Boost
Solenoid Circuit
High Voltage •
The ignition switch
is ON. •
The ECM detects
that the high
voltage condition on
the turbocharger
solenoid valve
control circuit for
longer than 3
seconds when the
solenoid valve is
commanded ON.
•
Turbocharger solenoid valve
control circuit is short to battery
or ignition voltage circuit.
• Faulty turbocharger solenoid
valve.
• Faulty ECM.

P0251 (6) 53 ON Injection Pump
Fuel Metering
Control •
The fuel injection
pump CMP sensor
signal is generated.
• The CAN
communication
between the ECM
and PCU is normal.
•
The PCU detects
that the fuel
injection solenoid
valve is operated
when the desired
fuel injection
quantity is
commanded 0
mg/strk.
•
Faulty fuel injection pump.
• Faulty PCU.


P0251 (7) 53 ON Injection Pump
Fuel Metering
Control •
The fuel injection
pump CMP sensor
signal is generated.
• The CKP sensor
signal is generated.
• The engine speed
is higher than 500
RPM.
•
The PCU detects
that the doubled
fuel injection pump
speed is lower than
engine speed by
690 RPM for longer
than 0.2 seconds.
•
Faulty CKP sensor signal.
• Faulty fuel injection pump CMP
sensor signal.
• Electrical interference.
• Magnetic interference.
• Faulty PCU.

P0251 (9) 53 ON Injection Pump
Fuel Metering
Control •
The ignition switch
is ON. •
The PCU detects
internal fuel
injection pump
control maps are
not programmed
during self-test.
•
Faulty PCU.


P0251 (A) 53 ON Injection Pump
Fuel Metering
Control •
The ignition switch
is ON. •
The PCU detects
internal EEPROM
or A/D converter is
failed during self-
test.
•
Faulty PCU.


P0251 (B) 53 ON Injection Pump
Fuel Metering
Control •
The ignition switch
is ON. •
The PCU detects
that the fuel
injection solenoid
valve drive circuit is
failed during self-
test.
•
Faulty fuel injection pump.
• Faulty PCU.


P0251 (D) 53 ON Injection Pump
Fuel Metering
Control •
The ignition switch
is ON. •
The PCU detects
that the fuel
injection solenoid
valve drive circuit
voltage level is
abnormal during
self-test.
•
Faulty fuel injection pump.
• Faulty PCU.



BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Control System (4JH1) 6E-55
DTC
(Symptom Code) Flash
Code MIL
Status DTC Name on
scan tool Condition for
Running the DTC Condition for
Setting the DTC Possible Cause
P0251
(E) 53 ON Injection Pump
Fuel Metering
Control •
The ignition switch
is ON. •
The ECM detects
communication
message from the
PCU is not received
for longer than 1
second.
•
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.

P0335 (B) 43 ON
Crankshaft
Position (CKP)
Sensor Circuit •
The ignition switch
is ON.
• The engine speed
is higher than 665
RPM.
•
The ECM detects
extra or missing
CKP sensor signals
while engine is
running. •
Sensor signal circuit is open
circuit, high resistance, short to
ground, short to battery or short
to ignition voltage.
• Sensor low reference circuit is
open circuit, high resistance,
short to ground, short to battery
or short to ignition voltage.
• Sensor shield ground is open
circuit, high resistance, short to
ground, short to battery or short
to ignition voltage.
• Faulty CKP sensor.
• Faulty ECM.
• Electrical interference.
• Magnetic interference.
• Faulty sensor installation.
• Faulty flywheel circumference.

P0335 (D) 43 ON
Crankshaft
Position (CKP)
Sensor Circuit •
DTC P0335
(Symptom Code B)
is not set.
• The ignition switch
is ON.
• The fuel injection
pump CMP sensor
signal is generated.
• The CAN
communication
between the ECM
and PCU is normal.
•
The ECM detects
that the CKP sensor
signals are not
generated when
doubled fuel
injection pump
rotation speed is
higher than 50
RPM.
•
Sensor signal circuit is open
circuit, high resistance, short to
ground, short to battery or short
to ignition voltage.
• Sensor low reference circuit is
open circuit, high resistance,
short to ground, short to battery
or short to ignition voltage.
• Sensor shield ground is open
circuit, high resistance, short to
ground, short to battery or short
to ignition voltage.
• Faulty CKP sensor.
• Faulty ECM.
• Electrical interference.
• Magnetic interference.
• Faulty sensor installation.
• Faulty flywheel circumference.

P0335 (E) 43 ON Crankshaft
Position (CKP)
Sensor Circuit •
Ignition switch is
ON.
•
The ECM detects
that the engine
speed is higher
than 5700 RPM for
0.2 seconds. •
Engine overrun.
• Faulty CKP sensor.
• Faulty ECM.
• Electrical interference.
• Magnetic interference.
• Faulty flywheel circumference.


BACK TO CHAPTER INDEX
TO MODEL INDEX
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.


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007