2007 ISUZU KB P190 ECO mode

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-203
DTC P0642 or P0643 (Flash Code 55)
Circuit Description
The ECM provides 5 volts reference voltage through
the reference circuit 1 to the accelerator pedal position
(APP) sensor 1. The ECM monitors the voltage on the
5 volts reference circuit 1. If the ECM detects the
voltage is excessively low or high, DTC P0642 or
P0643 will set.
Condition for Running the DTC • The battery voltage is more than 6 volts.
• The ignition switch is ON.
Condition for Setting the DTC • The ECM detects that the 5 volts reference circuit 1 voltage is less than 4.7 volts. (DTC P0642)
• The ECM detects that the 5 volts reference circuit 1 voltage is more than 5.3 volts. (DTC P0643)
Action Taken When the DTC Sets • The ECM illuminates the SVS lamp when the diagnostic runs and fails. Refer to DTC Type
Definitions for Action Taken When the DTC Sets -
Type C. (Euro 4 Specification) • 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.
(Except Euro 4 Specification)
• The ECM limits fuel injection quantity
• The ECM inhibits cruise control.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the SVS Lamp/ DTC - Type C. (Euro 4
Specification)
• Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A. (Except Euro 4
Specification)
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 P0642
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.
Does the DTC fail this ignition? —
Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition.
2. Disconnect the accelerator pedal position (APP) sensor harness connector.
3. Connect a DMM between the 5 volts reference circuit (pin 10 of C-40) and a known good
ground.
4. Turn ON the ignition, with engine OFF.
Is the DMM voltage more than the specified value? 4.7 volts
Go to Step 5 Go to Step 4
4 1. Test the 5 volts reference circuit between the
ECM (pin 11 of C-58) and the APP sensor (pin
10 of C-40) 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 7 Go to Step 6

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ISUZU KB P190 2007

6E-204 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Circuit/ System Testing DTC P0643
5Replace the APP sensor. Refer to APP Sensor
Replacement.
Did you complete the replacement? —
Go to Step 7
—
6Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 7
—
71. 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 8
8 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. Monitor the DTC Information with a scan tool.
Does the DTC fail this ignition? —
Go to Step 3 Go to Diagnostic
Aids
3 1. Test the 5 volts reference circuit between the
ECM (pin 11 of C-58) and the APP sensor 1
(pin 10 of C-40) 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 5 Go to Step 4
4 Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 5
—

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-205
51. 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 6
6 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-208 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
16Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 17
—
171. Reconnect all previously disconnected fuse or
harness connector(s).
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Perform the MIL Control with a scan tool.
5. Command the lamp ON and OFF.
Does the MIL turn ON and OFF with each
command? —
Go to Step 18 Go to Step 3
18 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

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-209
DTC P0652 or P0653 (Flash Code 56)
Circuit Description
The ECM provides 5 volts reference voltage through
the reference circuit 2 to the following sensors:
• Accelerator pedal position (APP) sensor 2
• Fuel rail pressure (FRP) sensor
• Barometric pressure (BARO) sensor
• Camshaft position (CMP) sensor
• EGR position sensor
The 5 volts reference circuits are independent of each
other outside the ECM, but are bussed together inside
the ECM. Therefore, a short circuit condition on one 5
volts reference circuit affects the entire 5 volts
reference circuit 2. The ECM monitors the voltage on
the 5 volts reference circuit 2. If the ECM detects the
voltage is excessively low or high, DTC P0652 or
P0653 will set.
Condition for Running the DTC • The battery voltage is more than 6 volts.
• The ignition switch is ON.
Condition for Setting the DTC • The ECM detects that the 5 volts reference circuit 2 voltage is less than 4.7 volts. (DTC P0652)
• The ECM detects that the 5 volts reference circuit 2 voltage is more than 5.3 volts. (DTC P0653) 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 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: • If this DTC is present, the engine cranks but does not start.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0652
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.
Does the DTC fail this ignition? —
Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition.
2. Disconnect the barometric pressure (BARO) sensor harness connector.
3. Connect a DMM between the 5 volts reference circuit (pin 3 of E-40) and a known good
ground.
4. Turn ON the ignition, with engine OFF.
Is the DMM voltage more than the specified value? 4.7 volts
Go to Step 9 Go to Step 4

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-211
Circuit/ System Testing DTC P0653
11Replace the FRP sensor. Refer to FRP Sensor
Replacement.
Did you complete the replacement? —
Go to Step 15
—
12Replace the CMP sensor. Refer to CMP Sensor
Replacement.
Did you complete the replacement? —
Go to Step 15
—
13Replace the APP sensor. Refer to APP Sensor
Replacement.
Did you complete the replacement? —
Go to Step 15
—
14Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 15
—
151. 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 16
16 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. Monitor the DTC Information with a scan tool.
Does the DTC fail this ignition? —
Go to Step 3 Go to Diagnostic
Aids

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ISUZU KB P190 2007

6E-212 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
31. Test the 5 volts reference circuit between the
ECM and the following components for a short
to battery or ignition voltage:
• ECM (pin 19 of E-90) and BARO sensor (pin 3 of E-40)
• ECM (pin 31 of E-90) and EGR position sensor (pin 1 of E-71)
• ECM (pin 47 of E-90) and FRP sensor (pin 3 of E-48)
• ECM (pin 46 of E-90) and CMP sensor (pin 3 of E-39)
• ECM (pin 9 of C-58) and APP sensor 2 (pin 8 of C-40)
2. Repair the circuit(s) as necessary.
Did you find and correct the condition? —
Go to Step 5 Go to Step 4
4 Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 5
—
51. 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 6
6 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

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-213
DTC P0661 or P0662 (Flash Code 58)
Circuit Description
The ECM controls the swirl levels, which energize the
swirl control solenoid valve based on the engine
running condition. The ECM commands the swirl
control solenoid valve to apply vacuum pressure to the
diaphragm actuator to operate swirl control butterflies
that is provided each intake port. If the ECM detects an
open circuit or short circuit on the solenoid valve circuit,
DTC P0661 or P0662 will set.
Condition for Running the DTC • The battery voltage is more than 9 volts.
• The ignition switch is ON.
Condition for Setting the DTC • The ECM detects a low voltage condition on the swirl control solenoid valve circuit when the
solenoid is commanded OFF. (DTC P0661)
• The ECM detects a high voltage condition on the swirl control solenoid valve circuit when the
solenoid is commanded ON. (DTC P0662)
Action Taken When the DTC Sets • The ECM illuminates the SVS lamp when the diagnostic runs and fails. Refer to DTC Type
Definitions for Action Taken When the DTC Sets -
Type C. (Euro 4 Specification) • 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.
(Except Euro 4 Specification)
• The ECM limits fuel injection quantity. (DTC P0661)
• The ECM inhibits cruise control. (DTC P0661)
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the SVS Lamp/ DTC - Type C. (Euro 4
Specification)
• Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type A. (Except Euro 4
Specification)
Diagnostic Aids • If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
Schematic Reference: Vacuum Hose Routing
Diagram and Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P0661
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. Monitor the DTC Information with a scan tool.
Does the DTC fail this ignition? —
Go to Step 3 Go to Diagnostic
Aids
3 1. Turn OFF the ignition.
2. Disconnect the swirl control solenoid valve harness connector.
3. Connect a test lamp between the ignition voltage feed circuit (pin 2 of E-67) 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 6

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TO MODEL INDEX
ISUZU KB P190 2007