2007 ISUZU KB P190 check engine

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-251
Circuit/ System Testing DTC P156B
51. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent, for a poor connection and for corrosion at the harness
connector of the ECM (pin 73 of C-58).
4. Repair the connection(s) as necessary.
Did you find and correct the condition? —
Go to Step 6 Go to Diagnostic
Aids
6 1. 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 and let idle.
5. Load the electrical system by turning ON the headlights, A/C, etc. while observing the
Battery Voltage parameter with a scan tool.
Does the scan tool indicate more than the specified
value? 10.0 volts
Go to Step 7 Go to Step 3
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
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 Was the vehicle recently jump started or a battery
charger placed on the battery? —
Go to Step 7 Go to Step 3
3 1. Install a scan tool.
2. Start the engine and let idle.
3. Observe the Battery Voltage parameter with the scan tool.
Does the scan tool indicate less than the specified
value? 16.0 volts
Go to Diagnostic Aids Go to Step 4
4 Test the charging system. Refer to Diagnosis of
The Charging System in the Charging System
Section.
Did you find a charging system problem? —
Go to Step 5 Go to Diagnostic
Aids
5 Repair the charging system. Refer to Diagnosis of
The Charging System in the Charging System
Section.
Did you complete the repair? —
Go to Step 6
—

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-253
DTC P161B (Flash Code 179)
Circuit Description
The ECM communicates with the immobilizer control
unit (ICU) to execute immobilizer function. The ECM
transmits a specific request signal to the ICU and the
ICU sends back a response signal to the ECM. Both
communication signals are carried out via a controller
area network (CAN) communication bus. If the ECM
receives a wrong response signal from the ICU, this
DTC will set.
Condition for Setting the DTC • The ECM receives a wrong immobilizer response signal from the ICU.
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)
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.
• Electromagnetic interference may affect intermittent condition.
Circuit/ System Testing DTC P161B
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.
Is DTC P0633, U0001 or U0167 also set? —
Go to Applicable DTC Go to Step 3
3 Monitor the immobilizer DTC Information with a
scan tool.
Does the immobilizer DTCs fail this ignition which
begin with B or U? —
Go to Applicable
DTC in Immobilizer Section Go to Step 4
4 Program immobilizer security information into the
ECM. Refer to Resetting and Programming
Guidelines in immobilizer section.
Did you find and correct the condition? —
Go to Step 6 Go to Step 5
5 Important:
Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement? —
Go to Step 6
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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-255
DTC P1621 (Flash Code 54, 254)
Circuit Description
The electrically erasable & programmable read only
memory (EEPROM) memorizes learning data, VIN data
and immobilzer security information. If the ECM detects
an error in either of their data, this DTC will set.
Condition for Running the DTC • The ignition switch is ON.
Condition for Setting the DTC
Either of following condition is met: • The ECM detects a faulty learning data in its internal EEPROM. (Flash Code 54)
• The ECM detects a faulty VIN data or immobilizer security information in its internal EEPROM. (Flash
Code 254) 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. (Flash Code 54)
• The ECM inhibits cruise control. (Flash Code 54)
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)
Circuit/ System Testing DTC P1621
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. Ensure that all tool connections are secure.
2. Ensure that programming equipment is operating correctly.
3. Install a scan tool.
4. Turn OFF the ignition for 30 seconds.
5. Turn ON the ignition, with the engine OFF.
6. Monitor the DTC Information with a scan tool.
Does the DTC fail this ignition? —
Go to Step 3 Go to Step 5
3 1. Verify the correct VIN and immobilizer code
are entered into the ECM with a scan tool.
Refer to ECM Replacement.
2. Turn OFF the ignition for 30 seconds.
3. Turn ON the ignition, with the engine OFF.
Does the DTC fail this ignition? —
Go to Step 4 Go to Step 5
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-257
DTC P1664 (Flash Code 76)
Circuit Description
The service vehicle soon (SVS) lamp is located on the
instrument panel (IP) cluster. The SVS lamp informs
the driver that a non-emission related fault has
occurred and vehicle service required.
The ECM monitors the SVS lamp control circuit for
conditions that are incorrect for the commanded state
of the SVS lamp. For example, a failure condition exists
if the ECM detects low voltage when the SVS lamp is
commanded OFF, or high voltage when the SVS lamp
is commanded ON. If the ECM detects an improper
voltage level on the control circuit, this DTC will set.
Condition for Running the DTC • The ignition voltage is more than 9 volts.
• The ignition switch is ON.
Condition for Setting the DTC
Low Voltage DTC • The ECM detects a low voltage condition on the SVS lamp control circuit when the lamp is
commanded OFF.
High Voltage DTC
• The ECM detects a high voltage condition on the SVS lamp control circuit when the lamp is
commanded ON. Action Taken When the DTC Sets
Low Voltage DTC • The ECM will not illuminate the MIL or SVS lamp.
• Refer to DTC Type Definitions for Action Taken When the DTC Sets - Type D.
High Voltage DTC
• 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.
Condition for Clearing the DTC
Low Voltage DTC • Refer to DTC Type Definitions for Condition for Clearing the DTC - Type D.
High Voltage DTC
• Refer to DTC Type Definitions for Condition for Clearing the SVS Lamp/ DTC - Type C.
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 P1664
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. Verify whether the instrument panel (IP)
cluster is operational.
2. Install a scan tool.
3. Perform the Service Vehicle Soon (SVS) Lamp Control with a scan tool.
4. Command the lamp ON and OFF.
Does the SVS lamp turn ON and OFF with each
command? —
Go to Diagnostic Aids Go to Step 3
3 1. Turn OFF the ignition.
2. Inspect the Meter (10A) fuse in the cabin fuse block.
Is the Meter (10A) fuse open? —
Go to Step 4 Go to Step 5
4 Replace the Meter (10A) fuse. If the fuse continues
to open, repair the short to ground on one of the
circuits that is fed by the Meter (10A) fuse or
replace the shorted attached component.
Did you complete the repair? —
Go to Step 17
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ISUZU KB P190 2007

6E-260 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
DTC P2100, P2101 or P2103 (Flash Code 446)
Circuit Description
The ECM controls the intake throttle valve opening
based on the engine running condition and by
controlling the intake throttle solenoid. The intake
throttle valve position is detected by the position
sensor, and relayed to the ECM. If the ECM detects an
open circuit or short circuit on the solenoid circuits,
DTC P2100, P2101 or P2103 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 an open circuit on the intake throttle solenoid circuits. (DTC P2100)
• The ECM detects a short to ground on the intake throttle solenoid circuits. (DTC P2101)
• The ECM detects a short to voltage circuit on the intake throttle solenoid circuits. (DTC P2103)
Action Taken When the DTC Sets • The ECM illuminates the MIL on the second consecutive driving cycle when the diagnostic runs
and fails. Refer to DTC Type Definitions for Action
Taken When the DTC Sets - Type B. (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 inhibits EGR control.
Condition for Clearing the DTC • Refer to DTC Type Definitions for Condition for Clearing the MIL/ DTC - Type B (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 P2100, P2101 or P2103
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 intake throttle valve harness connector.
3. Turn ON the ignition, with the engine OFF.
4. Connect a DMM between the drive voltage circuit (pin 2 of E-38) and a known good
ground.
5. Connect a DMM between the low side circuit (pin 1 of E-38) and a known good ground.
Are both voltage readings within the specified
value? 1.4 to 1.8 volts
Go to Step 5 Go to Step 4
4 Is the DMM voltage more than the specified value
at Step 3? —
Go to Step 7 Go to Step 6

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-263
DTC P2122 or P2123 (Flash Code 121)
Circuit Description
The accelerator pedal position (APP) sensor is
mounted on the accelerator pedal control assembly.
The sensor is made up of three individual sensors
within one housing. The ECM uses the APP sensors to
determine the amount of acceleration or deceleration
that is desired. The APP sensor 1 has the following
circuits.
• 5 volts reference circuit
• Low reference circuit
• APP sensor 1 signal circuit
The APP sensor 1 provides a signal to the ECM on the
signal circuit, which is relative to the position changes
of the accelerator pedal angle. If the ECM detects an
excessively low or high signal voltage, DTC P2122 or
P2123 will set.
Condition for Running the DTC • DTCs P0642 and P0643 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 APP sensor 1 signal voltage is less than 0.15 volts. (DTC P2122)
• The ECM detects that the APP sensor 1 signal voltage is more than 4.85 volts. (DTC P2123) 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.
• APP sensor 1 may have an intermittent open somewhere in the pedal range.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P2122
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 P0642 also set? —
Go to DTC P0642 Go to Step 3
3 Fully depress and release the accelerator pedal
while observing the Accelerator Pedal Position
(APP) Sensor 1 parameter with a scan tool.
Does the scan tool indicate less than the specified
value during depressing or releasing the pedal? 0.2 volts
Go to Step 4 Go to Diagnostic
Aids

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-265
Circuit/ System Testing DTC P2123
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. Fully depress and release the accelerator pedal while observing the APP Sensor 1
parameter with the scan tool.
Does the scan tool indicate less than the specified
value during depressing or releasing the pedal? 0.2 volts
Go to Step 3 Go to Step 13
13 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. Fully depress and release the accelerator pedal while observing the Accelerator Pedal
Position (APP) Sensor 1 parameter with a
scan tool.
Does the scan tool indicate more than the specified
value during depressing or releasing the pedal? 4.8 volts
Go to Step 3 Go to Diagnostic
Aids
3 Monitor the DTC Information with a scan tool.
Is DTC P0643 also set? —
Go to Step 4 Go to Step 5
4 1. Turn OFF the ignition.
2. Disconnect the APP sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
Is the APP Sensor 1 parameter less than the
specified value? 0.1 volts
Go to DTC P0643 Go to Step 7
5 1. Turn OFF the ignition.
2. Disconnect the APP sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
Is the APP Sensor 1 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 4 of C-40) and battery voltage.
Does the test lamp illuminate? —
Go to Step 9 Go to Step 8

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ISUZU KB P190 2007

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-267
DTC P2127 or P2128 (Flash Code 122)
Circuit Description
The accelerator pedal position (APP) sensor is
mounted on the accelerator pedal control assembly.
The sensor is made up of three individual sensors
within one housing. The ECM uses the APP sensors to
determine the amount of acceleration or deceleration
that is desired. The APP sensor 2 has the following
circuits.
• 5 volts reference circuit
• Low reference circuit
• APP sensor 2 signal circuit
The APP sensor 2 provides a signal to the ECM on the
signal circuit, which is relative to the position changes
of the accelerator pedal angle. If the ECM detects an
excessively low or high signal voltage, DTC P2127 or
P2128 will set.
Condition for Running the DTC • DTCs P0652 and P0653 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 APP sensor 2 signal voltage is less than 0.15 volts. (DTC P2127)
• The ECM detects that the APP sensor 2 signal voltage is more than 4.85 volts. (DTC P2128) 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.
• APP sensor 2 may have an intermittent open somewhere in the pedal range.
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Circuit/ System Testing DTC P2127
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 P0652 also set? —
Go to DTC P0652 Go to Step 3
3 Fully depress and release the accelerator pedal
while observing the Accelerator Pedal Position
(APP) Sensor 2 parameter with a scan tool.
Does the scan tool indicate less than the specified
value during depressing or releasing the pedal? 0.2 volts
Go to Step 4 Go to Diagnostic
Aids
4 1. Turn OFF the ignition.
2. Disconnect the APP sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
Is the APP Sensor 2 parameter more than the
specified value? 4.7 volts
Go to Step 5 Go to Step 6

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ISUZU KB P190 2007