2007 ISUZU KB P190 engine

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-105
91. Inspect for an intermittent and for a poor
connection at the harness connector of the
boost pressure sensor (pin 2 of E-107).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 11
10 1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor connection at the harness connector of the
ECM (pin 23 of E-90).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 12
11 Replace the boost pressure sensor. Refer to Boost
Pressure Sensor Replacement.
Did you complete the replacement? —
Go to Step 13
—
12Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 13
—
131. Reconnect all previously disconnected
harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the
vehicle within the conditions that you
observed from the Freeze Frame/ Failure
Records.
Did the DTC fail this ignition? —
Go to Step 2 Go to Step 14
14 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

6E-106 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0112 or P0113 (Flash Code 22)
Circuit Description
The intake air temperature (IAT) sensor is fitted
between the air cleaner and turbocharger. It is internal
to the mass air flow (MAF) sensor. The IAT sensor is a
variable resistor and it measures the temperature of the
air entering the engine. The sensor has a signal circuit
and a low reference circuit. The ECM supplies 5 volts to
the signal circuit and a ground for the low reference
circuit. When the IAT sensor is cold, the sensor
resistance is high. When the air temperature increases,
the sensor resistance decreases. With high sensor
resistance, the ECM detects a high voltage on the
signal circuit. With lower sensor resistance, the ECM
detects a lower voltage on the signal circuit. If the ECM
detects an excessively low or high signal voltage, DTC
P0112 or P0113 will set.
Condition for Running the DTC • The battery voltage is more than 9 volts.
• The ignition switch is ON.
• The engine run time is longer than 3 minutes. (DTC P0113)
Condition for Setting the DTC • The ECM detects that the IAT sensor signal voltage is less than 0.1 volts for 3 seconds. (DTC
P0112) • The ECM detects that the IAT sensor signal
voltage is more than 4.75 volts for 3 seconds.
(DTC P0113)
Action Taken When the DTC Sets • The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
• The ECM uses an IAT substitution of default value.
• The ECM limits fuel injection quantity.
• The ECM inhibits EGR control.
• The ECM inhibits cruise control.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A.
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 driveability
concerns.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0112
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 a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Turn ON the ignition, with the engine OFF.
4. Observe the Intake Air Temperature (IAT) Sensor parameter with a scan tool.
Is the IAT Sensor parameter less than the specified
value? 0.1 volts
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.
Is the IAT Sensor parameter more than the
specified value? 4.7 volts
Go to Step 5 Go to Step 4

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-107
Circuit/ System Testing DTC P0113
41. Test the signal circuit between the ECM (pin
41 of E-90) and the IAT sensor (pin 4 of E-47)
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
5 Replace the MAF sensor. Refer to MAF Sensor
Replacement. (IAT sensor is internal to MAF
sensor)
Did you complete the replacement? —
Go to Step 8
—
61. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect connections at the harness connector of the ECM (pins 41 and 61 of E-90) 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 and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 8
—
81. Reconnect all previously disconnected
harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the
vehicle within the conditions that you
observed from the Freeze Frame/ Failure
Records.
Did the DTC fail this ignition? —
Go to Step 2 Go to Step 9
9 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No
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 a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Turn ON the ignition, with the engine OFF.
4. Observe the Intake Air Temperature (IAT) Sensor parameter with a scan tool.
Is the IAT Sensor parameter more than the
specified value? 4.7 volts
Go to Step 3 Go to Diagnostic
Aids

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ISUZU KB P190 2007

6E-108 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
31. 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 (pin 4 of E-47) and a known good ground.
4. Turn ON the ignition, with the engine OFF.
Is the DMM voltage more than the specified value? 5.3 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 ECM (pin 41 of E-90) and the IAT sensor (pin 4 of E-47)
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
5 Connect a 3-amp fused jumper wire between the
signal circuit and the low reference circuit (pins 4
and 5 of E-47).
Is the IAT Sensor parameter less than the specified
value? 0.1 volts
Go to Step 9 Go to Step 6
6 Connect a 3-amp fused jumper wire between the
signal circuit (pin 4 of E-47) and a known good
ground.
Is the IAT Sensor parameter less than the specified
value? 0.1 volts
Go to Step 8 Go to Step 7
7 1. Test the signal circuit between the ECM (pin
41 of E-90) and the IAT sensor (pin 4 of E-47)
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 61 of E-90) and the IAT sensor (pin
5 of E-47) 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
41 of E-90) and the IAT sensor (pin 4 of E-47)
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. Inspect for an intermittent and for poor
connections at the harness connector of the
IAT sensor (pins 4 and 5 of E-47).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 14 Go to Step 12
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-109
111. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for poor connections at the harness connector of the
ECM (pins 41 and 61 of E-90).
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 MAF sensor. Refer to MAF Sensor
Replacement. (IAT sensor is internal to MAF
sensor)
Did you complete the replacement? —
Go to Step 14
—
13Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 14
—
141. Reconnect all previously disconnected
harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the
vehicle within the conditions that you
observed from the Freeze Frame/ Failure
Records.
Did the DTC fail this ignition? —
Go to Step 2 Go to Step 15
15 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

6E-110 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0116 (Flash Code 23)
Circuit Description
The engine coolant temperature (ECT) sensor is
installed to the thermostat housing. The ECT sensor is
a variable resistor and it measures the temperature of
the engine coolant. If the ECM detects that the
difference of engine coolant temperature is smaller
than the calculated range during the predetermined
conditions, this DTC will set. This DTC will only run
once per ignition cycle within the enabling condition.
Condition for Running the DTC • DTCs P0117, P0118, P0201 - P0204, P0500, P0501 P124B, P1261, P1262 and P2146 - P2151
are not set.
• The ignition switch is ON.
• The engine coolant temperature is between -10 to 11 0 °C (14 to 230 °F).
• The vehicle run time is longer than 18 minutes.
• The engine run time is longer than 5 minutes with engine speed is more than 1200 RPM.
• The accumulation fuel injection quantity since engine start is more than a threshold.
Condition for Setting the DTC • The ECM detects that the difference of maximum and minimum engine coolant temperature is less
than 5 °C (9 °F). Action Taken When the DTC Sets
• The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
• The ECM limits fuel injection quantity.
• The ECM inhibits EGR control.
• The ECM inhibits cruise control.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A.
Diagnostic Aids • After starting the engine the ECT should rise steadily to about 80 to 85 °C (176 to 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 driveability
concerns.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0116
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. Test the engine cooling system for the
following condition. Refer to diagnosis of the
engine cooling system section for testing.
• Engine coolant level
• Engine coolant leakage
2. Repair or replace as necessary
Did you find and correct the condition? —
Go to Step 6 Go to Step 3
3 1. Turn OFF the ignition
2. Disconnect the engine coolant temperature (ECT) sensor harness connector.
3. Inspect for an intermittent, for poor connectors and corrosion at the harness connector of the
ECT sensor (pins 1 and 2 of E-41).
4. Disconnect the ECM harness connector.
5. Inspect for an intermittent, for poor connections and corrosion at the harness
connector of the ECM (pins 26 and 27 of E-
90).
6. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 6 Go to Step 4

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-111
41. Test each sensor circuit between the ECM
(pins 26 and 27 of E-90) and the ECT sensor
(pins 1 and 2 of E-41) for high resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 6 Go to Step 5
5 Replace the ECT sensor. Refer to ECT Sensor
Replacement.
Did you complete the replacement? —
Go to Step 6
—
61. Reconnect all previously disconnected
harness connector(s).
2. Clear the DTCs with a 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 and wait until engine is warm upped while comparing the Coolant
Temperature parameter on the scan tool to the
water temperature gauge on the instrument
panel (IP) cluster.
Does the Coolant Temperature rise from 50 to 80 °C
(122 to 176 °F) in proportion to the coolant
temperature gauge indicates from lowest scale to
slightly below middle? —
Go to Step 7 Go to Step 2
7 Observe the DTC Information with a scan tool.
Are there any DTCs that you have not diagnosed? —
Go to DTC List System OK
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

6E-112 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0117 or P0118 (Flash Code 23)
Circuit Description
The engine coolant temperature (ECT) sensor is
installed to the thermostat housing. The ECT sensor is
a variable resistor and it measures the temperature of
the engine coolant. The sensor has a signal circuit and
a low reference circuit. The ECM supplies 5 volts to the
signal circuit and a ground for the low reference circuit.
When the ECT sensor is cold, the sensor resistance is
high. When the engine coolant temperature increases,
the sensor resistance decreases. With high sensor
resistance, the ECM detects a high voltage on the
signal circuit. With lower sensor resistance, the ECM
detects a lower voltage on the signal circuit. If the ECM
detects an excessively low or high signal voltage, DTC
P0117 or P0118 will set.
Condition for Running the DTC • The battery voltage is more than 9 volts.
• The ignition switch is ON.
• The engine run time is longer than 3 minutes. (DTC P0118)
Condition for Setting the DTC • The ECM detects that the ECT sensor signal voltage is less than 0.1 volts for 3 seconds. (DTC
P0117)
• The ECM detects that the ECT sensor signal voltage is more than 4.75 volts for 3 seconds.
(DTC P0118) Action Taken When the DTC Sets
• The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
• The ECM uses an ECT substitution of default value.
• The ECM limits fuel injection quantity.
• The ECM inhibits EGR control.
• The ECM inhibits cruise control.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A.
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
• 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 driveability
concerns.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0117
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 a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Turn ON the ignition, with the engine OFF.
4. Observe the Engine Coolant Temperature (ECT) Sensor parameter with a scan tool.
Is the ECT Sensor parameter less than the
specified value? 0.1 volts
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.
Is the ECT Sensor parameter more than the
specified value? 4.7 volts
Go to Step 5 Go to Step 4

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TO MODEL INDEX
ISUZU KB P190 2007