2007 ISUZU KB P190 engine

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-97
7Observe 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-98 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0102 or P0103 (Flash Code 91)
Circuit Description
The mass air flow (MAF) sensor is an air flow meter
that measures the amount of air that enters the engine.
It is fitted between the air cleaner and turbocharger. A
small quantity of air that enters the engine indicates
deceleration or idle speed. A large quantity of air that
enters the engine indicates acceleration or a high load
condition. The sensor has the following circuits.
• Ignition voltage circuit
• Low reference circuit
• MAF sensor signal circuit
The ECM monitors the MAF sensor signal voltage. This
output voltage will display on the scan tool as a voltage
parameter and as a grams per second (g/s) parameter.
If the ECM detects an excessively low or high signal
voltage, DTC P0102 or P0103 will set.
Condition for Running the DTC • The battery voltage is between 11.5 to 16.0 volts.
• The ignition switch is ON.
• The engine is running.
Condition for Setting the DTC • The ECM detects that the MAF sensor signal voltage is less than 0.1 volts. (DTC P0102)
• The ECM detects that the MAF sensor signal voltage is more than 4.9 volts for 3 seconds. (DTC
P0103)
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 a MAF substitution of default value.
• The ECM limits fuel injection quantity.
• The ECM inhibits pilot injection.
• 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.
Notice: • The MAF Sensor parameter on scan tool will only update with engine running or one time after the
key is cycled when the ignition has been turned
OFF for longer than 10 seconds.
Test description
The number below refers to the step number on the
Circuit/ System Testing.
DTC P0102
4. This step tests for proper operation of the circuit in
the signal circuit. If the fuse in the jumper opens when
you perform this test, the signal circuit is shorted to
ground or low reference circuits.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0102
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. Start the engine.
4. Observe the Mass Air Flow (MAF) Sensor parameter with a scan tool.
Is the MAF Sensor parameter less than the
specified value? 0.1 volts
Go to Step 3 Go to Diagnostic
Aids

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-99
31. Turn OFF the ignition.
2. Disconnect the MAF sensor harness connector.
3. Connect a test lamp between the ignition voltage feed circuit (pin 1 of E-47) and a
known good ground.
4. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate? —
Go to Step 4 Go to Step 5
4 1. Turn OFF the ignition for 30 seconds.
2. Connect a 3-amp fused jumper wire between the ignition voltage feed circuit and the signal
circuit (pins 1 and 3 of E-47).
3. Turn ON the ignition, with the engine OFF.
Is the MAF Sensor parameter more than the
specified value? 4.9 volts
Go to Step 7 Go to Step 6
5 Repair the open circuit or high resistance between
the ECM Main Relay (pin 1 of X-12) and the MAF
sensor (pin 1 of E-47) for and open circuit or high
resistance. Check the Engine (10A) fuse first.
Did you complete the repair? —
Go to Step 11
—
61. Test the signal circuit between the ECM (pin
40 of E-90) and the MAF sensor (pin 3 of E-
47) for the following conditions:
• An open circuit
• A short to ground
• A short to the low reference circuit
• High resistance
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 8
7 1. Inspect for an intermittent and for poor
connections at the harness connector of the
MAF sensor (pins 1 and 3 of E-47).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 9
8 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 40 of E-90).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 10
9 Replace the MAF sensor. Refer to MAF Sensor
Replacement.
Did you complete the replacement? —
Go to Step 11
—
10Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 11
—
Step Action Value(s)Yes No

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ISUZU KB P190 2007

6E-100 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Circuit/ System Testing DTC P0103
111. Reconnect all previously disconnected fuse,
relay or 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 12
12 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. Start the engine.
4. Observe the Mass Air Flow (MAF) Sensor parameter with a scan tool.
Is the MAF Sensor parameter more than the
specified value? 4.9 volts
Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition for 30 seconds.
2. Disconnect the MAF sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
Is the MAF Sensor parameter less than the
specified value? 0.1 volts
Go to Step 4 Go to Step 5
4 Connect a test lamp between the low reference
circuit (pin 2 of E-47) and battery voltage.
Does the test lamp illuminate? —
Go to Step 7 Go to Step 6
5 1. Test the signal circuit between the ECM (pin
40 of E-90) and the MAF sensor (pin 3 of E-
47) for the following conditions:
• A short to battery or ignition voltage
• A short to any 5 volts reference
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 10
6 1. Test the low reference circuit between the
ECM (pin 43 of E-90) and the MAF sensor (pin
2 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 11 Go to Step 8

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-101
71. Inspect for an intermittent and for a poor
connection at the harness connector of the
MAF sensor (pin 2 of E-47).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 9
8 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 43 of E-90).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 11 Go to Step 10
9 Replace the MAF sensor. Refer to MAF Sensor
Replacement.
Did you complete the replacement? —
Go to Step 11
—
10Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 11
—
111. 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 12
12 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-102 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P0107 or P0108 (Flash Code 32)
Circuit Description
The boost pressure sensor is located in the air
induction tubing. The boost pressure sensor is a
transducer that varies voltage according to changes in
the air pressure inside the air tubing. The sensor has
the following circuits.
• 5 volts reference circuit
• Low reference circuit
• Boost pressure sensor signal circuit
The boost pressure sensor provides a signal to the
ECM on the signal circuit, which is relative to the
pressure changes in the air tubing. The ECM should
detect a low signal voltage at a low boost pressure,
such as low engine load. The ECM should detect high
signal voltage at a high boost pressure, such as high
engine load. If the ECM detects an excessively low or
high signal voltage, DTC P0107 or P0108 will set.
Condition for Running the DTC • DTCs P0698 and P0699 are not set.
• The battery voltage is more than 9 volts.
• The ignition switch is ON.
Condition for Setting the DTC • The ECM detects that the boost pressure sensor signal voltage is less than 0.1 volts. (DTC P0107) • The ECM detects that the boost pressure sensor
signal voltage is more than 4.75 volts. (DTC
P0108)
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 a boost pressure 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.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0107
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. Start the engine.
4. Monitor the DTC Information with a scan tool.
Is DTC P0698 also set? —
Go to DTC P0698 Go to Step 3
3 Observe the Boost Pressure Sensor parameter
with a scan tool.
Is the Boost Pressure Sensor parameter less than
the specified value? 0.1 volts
Go to Step 4 Go to Diagnostic
Aids
4 1. Turn OFF the ignition.
2. Disconnect the boost pressure sensor harness connector.
3. Connect a DMM between the 5 volts reference circuit (pin 3 of E-107) and a known good
ground.
4. Turn ON the ignition, with the engine OFF.
Is the DMM voltage more than the specified value? 4.7 volts
Go to Step 5 Go to Step 6

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-103
5Connect a 3-amp fused jumper wire between the 5
volts reference circuit and the signal circuit (pins 3
and 1 of E-107).
Is the Boost Pressure Sensor parameter more than
the specified value? 4.7 volts
Go to Step 8 Go to Step 7
6 1. Test the 5 volts reference circuit between the
ECM (pin 20 of E-90) and the boost pressure
sensor (pin 3 of E-107) for an open circuit or
high resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 12 Go to Step 9
7 1. Test the signal circuit between the ECM (pin
21 of E-90) and the boost pressure sensor
(pin 1 of E-107) for the following conditions:
• An open circuit
• A short to ground
• A short to the low reference circuit
• High resistance
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 12 Go to Step 9
8 1. Inspect for an intermittent and for poor
connections at the harness connector of the
boost pressure sensor (pins 1 and 3 of E-107).
2. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 12 Go to Step 10
9 1. 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 20 and 21 of E-90).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 12 Go to Step 11
10 Replace the boost pressure sensor. Refer to Boost
Pressure Sensor Replacement.
Did you complete the replacement? —
Go to Step 12
—
11Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 12
—
121. 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 3 Go to Step 13
Step
Action Value(s)Yes No

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ISUZU KB P190 2007

6E-104 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Circuit/ System Testing DTC P0108
13Observe 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. Start the engine.
4. Observe the Boost Pressure Sensor parameter with a scan tool.
Is the Boost Pressure Sensor parameter more than
the specified value? 4.7 volts
Go to Step 3 Go to Diagnostic
Aids
3 Monitor the DTC Information with a scan tool.
Is DTC P0699 also set? —
Go to Step 4 Go to Step 5
4 1. Turn OFF the ignition.
2. Disconnect the boost pressure sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
Is the Boost Pressure Sensor parameter less than
the specified value? 0.1 volts
Go to DTC P0699 Go to Step 7
5 1. Turn OFF the ignition.
2. Disconnect the boost pressure sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
Is the Boost Pressure Sensor parameter less than
the specified value? 0.1 volts
Go to Step 6 Go to Step 7
6 Connect a test lamp between the low reference
circuit (pin 2 of E-107) and battery voltage.
Does the test lamp illuminate? —
Go to Step 9 Go to Step 8
7 Important:
The boost pressure sensor may be
damaged if the sensor signal circuit is shorted to a
voltage source.
1. Test the signal circuit between the ECM (pin 21 of E-90) and the boost pressure sensor
(pin 1 of E-107) for the following conditions:
• A short to battery or ignition voltage
• A short to any 5 volts reference
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 12
8 1. Test the low reference circuit between the
ECM (pin 23 of E-90) and the boost pressure
sensor (pin 2 of E-107) for an open circuit or
high resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 13 Go to Step 10

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ISUZU KB P190 2007