2007 ISUZU KB P190 sensor

Engine Control System (4JH1) 6E-85
DTC P0110 (Symptom Code 1) (Flash Code 23)
Circuit Description
The intake air temperature (IAT) sensor is fitted
between the air cleaner and turbocharger internal to the
mass air flow (MAF) sensor. The IAT sensor is a
variable resistor. The IAT sensor has a signal circuit
and a low reference circuit. The IAT sensor measures
the temperature of the air entering the engine. The
engine control module (ECM) supplies 5 volts to the IAT
signal circuit and a ground for the IAT low reference
circuit. W hen the IAT sensor is cold, the senso
r
resistance is high. W hen the air temperature increases,
the sensor resistance decreases. W ith high senso
r
resistance, the ECM detects a high voltage on the IAT
signal circuit. W ith lower sensor resistance, the ECM
detects a lower voltage on the IAT signal circuit. If the
ECM detects an excessively high IAT signal 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 IAT sensor signal
voltage is more than 4.7 volts for 3 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 an IAT substitution of 0 °C (32 °F)
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
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
• Use the Temperature vs. Resistance table to test
the IAT sensor at various temperature levels to
evaluate the possibility of a skewed sensor.
A
skewed sensor could result in poor driveabilit
y
concerns.
Notice: • The mass air flow (MAF) sensor is heated and as
a result the IAT sensor may indicate a higher than
normal intake temperature if the ignition switch is
being ON.

DTC P0110 (Symptom Code 1) (Flash Code 23)
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. Observe the Intake Air Temperature (IAT) parameter with the scan tool.
Is the IAT parameter less than the specified value? -38°C (-36°F)
Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition. 2. Disconnect the mass air flow/intake air temperature (MAF/IAT) sensor harness
connector.
3. Connect a DMM between the signal circuit of the IAT sensor harness (pin 1 of C-116 connector)
and a known good ground.
4. Turn ON the ignition, with the engine OFF.
Is the DMM voltage more than the specified value? 5.5 volts
Go to Step 4 Go to Step 5
4 Important: The IAT sensor may be damaged if the
sensor signal circuit is shorted to a voltage source.
1. Test the signal circuit between the engine control module (ECM) (pin 84 of C-57 connector) and
the IAT sensor (pin 1 of C-116 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 14 Go to Step 13

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ISUZU KB P190 2007

6E-86 Engine Control System (4JH1)
Step Action Value(s) Yes No
5 1. Turn OFF the ignition.
2. Connect a 3-amp fused jumper wire between the signal circuit and the low reference circuit of the
IAT sensor harness (pins 1 and 3 of C-116
connector).
3. Turn ON the ignition, with the engine OFF.
4. Observe the IAT parameter with the scan tool.
Is the IAT parameter more than the specified value? 110°C (230°F)
Go to Step 9 Go to Step 6
6 1. Turn OFF the ignition. 2. Connect a 3-amp fused jumper wire between the signal circuit of the IAT sensor harness (pin 1 of
C-116 connector) and a known good ground.
3. Turn ON the ignition, with the engine OFF.
4. Observe the IAT parameter with the scan tool.
Is the IAT parameter more than the specified value? 110°C (230°F)
Go to Step 8 Go to Step 7
7 1. Test the signal circuit between the ECM (pin 84 of C-57 connector) and the IAT sensor (pin 1 of
C-116 connector) for an open circuit high
resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 14 Go to Step 11
8 1. Test the low reference circuit between the ECM (pin 92 of C-57 connector) and the IAT sensor
(pin 3 of C-116 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 14 Go to Step 11
9 1. Test the signal circuit between the ECM (pin 84 of C-57 connector) and the IAT sensor (pin 1 of
C-116 connector) for a short to any 5 volts
reference circuit.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 14 Go to Step 10
10 1. Turn OFF the ignition. 2. Inspect for an intermittent and for poor connections at the harness connector of the IAT
sensor (pins 1 and 3 of C-116 connector).
3. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 14 Go to Step 12
11 1. Turn OFF the ignition. 2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for poor connections on the IAT sensor circuits at the
harness connector of the ECM (pins 84 and 92 of
C-57 connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 14 Go to Step 13
12 Replace the IAT sensor. Refer to Mass Air Flow Sensor Replacement in this section. (IAT sensor is
internal to MAF sensor)
Did you complete the replacement? 

Go to Step 14 
13 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 14 

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ISUZU KB P190 2007

6E-88 Engine Control System (4JH1)
DTC P0110 (Symptom Code 2) (Flash Code 23)
Circuit Description
The intake air temperature (IAT) sensor is fitted
between the air cleaner and turbocharger internal to the
mass air flow (MAF) sensor. The IAT sensor is a
variable resistor. The IAT sensor has a signal circuit
and a low reference circuit. The IAT sensor measures
the temperature of the air entering the engine. The
engine control module (ECM) supplies 5 volts to the IAT
signal circuit and a ground for the IAT low reference
circuit. W hen the IAT sensor is cold, the senso
r
resistance is high. W hen the air temperature increases,
the sensor resistance decreases. W ith high senso
r
resistance, the ECM detects a high voltage on the IAT
signal circuit. W ith lower sensor resistance, the ECM
detects a lower voltage on the IAT signal circuit. If the
ECM detects an excessively low IAT signal 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 IAT sensor signal
voltage is less than 0.3 volts for 3 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 an IAT substitution of 0 °C (32 °F)
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
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
• Use the Temperature vs. Resistance table to test
the IAT sensor at various temperature levels to
evaluate the possibility of a skewed sensor.
A
skewed sensor could result in poor driveabilit
y
concerns.
Notice: • The mass air flow (MAF) sensor is heated and as
a result the IAT sensor may indicate a higher than
normal intake temperature if the ignition switch is
being ON.

DTC P0110 (Symptom Code 2) (Flash Code 23)
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. Observe the Intake Air Temperature (IAT) parameter with the scan tool.
Is the IAT parameter more than the specified value? 110°C (230°F)
Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition. 2. Disconnect the mass air flow/intake air temperature (MAF/IAT) sensor harness
connector.
3. Turn ON the ignition, with the engine OFF.
4. Observe the IAT parameter with the scan tool.
Is the IAT parameter less than the specified value? -38°C (-36°F)
Go to Step 5 Go to Step 4
4 1. Test the signal circuit between the engine control module (ECM) (pin 84 of C-57 connector) and
the IAT sensor (pin 1 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 8 Go to Step 6

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-89
Step Action Value(s) Yes No
5 Replace the IAT sensor. Refer to Mass Air Flow
Sensor Replacement in this section. (IAT sensor is
internal to MAF sensor)
Did you complete the replacement? 

Go to Step 8 
6 1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect connections on the IAT sensor circuits at the harness connector of the ECM (pins 84 and
92 of C-57 connector) for corrosion.
4. Repair or clean the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 8 Go to Step 7
7 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 8 
8 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. 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 9
9 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

6E-90 Engine Control System (4JH1)
DTC P0115 (Symptom Code 1) (Flash Code 14)
Circuit Description
The engine coolant temperature (ECT) sensor is
installed to the thermostat housing. The ECT sensor is
a variable resistor. The ECT sensor has a signal circuit
and a low reference circuit. The ECT sensor measures
the temperature of the engine coolant. The engine
control module (ECM) supplies 5 volts to the ECT signal
circuit and a ground for the ECT low reference circuit.
W hen the ECT sensor is cold, the sensor resistance is
high. W hen the engine coolant temperature increases,
the sensor resistance decreases. W ith high senso
r
resistance, the ECM detects a high voltage on the ECT
signal circuit. W ith lower sensor resistance, the ECM
detects a lower voltage on the ECT signal circuit. If the
ECM detects an excessively high ECT signal 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 ECT sensor signal
voltage is more than 4.7 volts for 3 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 an ECT substitution of fuel
temperature for engine control.

•
The ECM uses an ECT substitution of 60 °C
(120 °F) for injection timing control.
• The ECM uses an ECT substitution of -15 °C (5 °F)
for glow 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
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
•
After starting the engine, the ECT should rise
steadily to about 80°C – 85°C (176°F – 185°F)
then stabilize when the thermostat opens.
• Use the Temperature vs. Resistance table to test
the ECT sensor at various temperature levels to
evaluate the possibility of a skewed sensor.
A
skewed sensor could result in poor driveabilit
y
concerns.


DTC P0115 (Symptom Code 1) (Flash Code 14)
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. Observe the Engine Coolant Temperature (ECT) parameter with the scan tool.
Is the ECT parameter less than the specified value? -35°C (-31°F)
Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition. 2. Disconnect the ECT sensor harness connector.
3. Connect a DMM between the signal circuit of the ECT sensor harness (pin 1 of E-41 connector)
and a known good ground.
4. Turn ON the ignition, with the engine OFF.
Is the DMM voltage more than the specified value? 5.5 volts
Go to Step 4 Go to Step 5
4 Important: The ECT sensor may be damaged if the
sensor signal circuit is shorted to a voltage source.
1. Test the signal circuit between the engine control module (ECM) (pin 89 of C-57 connector) and
the ECT sensor (pin 1 of E-41 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 14 Go to Step 13

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-91
Step Action Value(s) Yes No
5 1. Turn OFF the ignition.
2. Connect a 3-amp fused jumper wire between the signal circuit and the low reference circuit of the
ECT sensor harness (pins 1 and 2 of E-41
connector).
3. Turn ON the ignition, with the engine OFF.
4. Observe the ECT parameter with the scan tool.
Is the ECT parameter more than the specified
value? 135°C (275°F)
Go to Step 9 Go to Step 6
6 1. Turn OFF the ignition. 2. Connect a 3-amp fused jumper wire between the signal circuit of the ECT sensor harness (pin 1 of
E-41 connector) and a known good ground.
3. Turn ON the ignition, with the engine OFF.
4. Observe the ECT parameter with the scan tool.
Is the ECT parameter more than the specified
value? 135°C (275°F)
Go to Step 8 Go to Step 7
7 1. Test the signal circuit between the ECM (pin 89 of C-57 connector) and the ECT sensor (pin 1 of
E-41 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 14 Go to Step 11
8 1. Test the low reference circuit between the ECM (pin 93 of C-57 connector) and the ECT sensor
(pin 2 of E-41 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 14 Go to Step 11
9 1. Test the signal circuit between the ECM (pin 89 of C-57 connector) and the ECT sensor (pin 1 of
E-41 connector) for a short to any 5 volts
reference circuit.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? 

Go to Step 14 Go to Step 10
10 Turn OFF the ignition. Inspect for an intermittent and for poor connections
at the harness connector of the ECT sensor (pins 1
and 2 of E-41 connector).
Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 14 Go to Step 12
11 1. Turn OFF the ignition. 2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for poor connections on the ECT sensor circuits at the
harness connector of the ECM (pins 89 and 93 of
C-57 connector).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 14 Go to Step 13
12 Replace the ECT sensor. Refer to Engine Coolant Temperature Sensor Replacement in this section.
Did you complete the replacement? 

Go to Step 14 
13 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 14 

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TO MODEL INDEX
ISUZU KB P190 2007

Engine Control System (4JH1) 6E-93
DTC P0115 (Symptom Code 2) (Flash Code 14)
Circuit Description
The engine coolant temperature (ECT) sensor is
installed to the thermostat housing. The ECT sensor is
a variable resistor. The ECT sensor has a signal circuit
and a low reference circuit. The ECT sensor measures
the temperature of the engine coolant. The engine
control module (ECM) supplies 5 volts to the ECT signal
circuit and a ground for the ECT low reference circuit.
W hen the ECT sensor is cold, the sensor resistance is
high. W hen the engine coolant temperature increases,
the sensor resistance decreases. W ith high senso
r
resistance, the ECM detects a high voltage on the ECT
signal circuit. W ith lower sensor resistance, the ECM
detects a lower voltage on the ECT signal circuit. If the
ECM detects an excessively low ECT signal 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 ECT sensor signal
voltage is less than 0.3 volts for 3 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 an ECT substitution of fuel
temperature for engine control.

•
The ECM uses an ECT substitution of 60 °C
(120 °F) for injection timing control.
• The ECM uses an ECT substitution -15 °C (5 °F) fo
r
glow 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
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
•
After starting the engine, the ECT should rise
steadily to about 80°C – 85°C (176°F – 185°F)
then stabilize when the thermostat opens.
• Use the Temperature vs. Resistance table to test
the ECT sensor at various temperature levels to
evaluate the possibility of a skewed sensor.
A
skewed sensor could result in poor driveabilit
y
concerns.

DTC P0115 (Symptom Code 2) (Flash Code 14)
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. Observe the Engine Coolant Temperature (ECT) parameter with the scan tool.
Is the ECT parameter more than the specified value? 135°C (275°F)
Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition. 2. Disconnect the ECT sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Observe the Coolant Temperature parameter with the scan tool.
Is the ECT parameter less than the specified value? -35°C (-31°F)
Go to Step 5 Go to Step 4
4 1. Test the signal circuit between the engine control module (ECM) (pin 89 of C-57 connector) and
the ECT sensor (pin 1 of E-41 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 8 Go to Step 6

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ISUZU KB P190 2007

6E-94 Engine Control System (4JH1)
Step Action Value(s) Yes No
5 Replace the ECT sensor. Refer to Engine Coolant
Temperature Sensor Replacement in this section.
Did you complete the replacement? 

Go to Step 8 
6 1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect connections on the ECT sensor circuits at the harness connector of the ECM (pins 89
and 93 of C-57 connector) for corrosion.
4. Repair or clean the connection(s) as necessary.
Did you find and correct the condition? 

Go to Step 8 Go to Step 7
7 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 8 
8 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. 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 9
9 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