2007 ISUZU KB P190 IMMOBILISER

Engine Management – V6 – Diagnostics Page 6C1-2–165

Step Action Yes
No
10 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does DTC P0850 fail this ignition cycle? Go to Step 2 Go to Step 11
11 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.
7.43 DTC P1648
DTC Descriptor
This diagnostic procedure supports DTC P1648 – W rong Security Code Entered.
Circuit Description
Tech 2 is used to program the engine control module (ECM). Before any programming, a security code must be entered
into Tech 2. The ECM will check if the code entered is correct before continuing. If the security code is incorrect, DTC
P1648 sets.
Conditions for Running the DTC
Conditions for running the DTC are:
• The ignition is switched on.
• The ignition voltage is 10.0 – 16.0 V.
Conditions for Setting the DTC
An incorrect security code is entered into Tech 2 when attempting to program the ECM.
Action Taken When the DTC Sets
W hen the DTC sets, the malfunction indicator lamp (MIL) is not displayed.
Conditions for Clearing the DTC
The immobiliser security code is a Type ‘C’ DTC. Refer to 1.4 Diagnostic Trouble Codes in this Section, for action
taken when a Type ‘C’ DTC sets and conditions for clearing Type ‘C’ DTCs.
Additional Information
• Refer to 6C1-1 Engine Management –V6 – General Information for details of the ECM operation.
• Refer to 6C1-3 Engine Management –V6 – Service Operations for details on resetting the ECM.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.

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Engine Management – V6 – Diagnostics Page 6C1-2–218

6 1 Test the pump current circuit of the HO2S for an
open. Refer to 8A Electrical-Body and Chassis.
Did you find and correct the condition? —
Go to Step 11 Go to Step 8
7 1 Test for an intermittent and for a poor connection
at the appropriate HO2S. Refer to 8A Electrical-
Body and Chassis.
Did you find and correct the condition? —
Go to Step 11 Go to Step 9
8 1 Test for an intermittent and for a poor connection
at the engine control module (ECM). Refer to 8A
Electrical-Body and Chassis.
Did you find and correct the condition? —
Go to Step 11 Go to Step 10
9 1 Replace the HO2S. Refer to 6C1-3 Engine
Management – V6 – Service Operations.
Did you complete the replacement? —
Go to Step 11 —
10 1 Replace the ECM. Refer to 6C1-3 Engine
Management –V6 – Service Operations for
details on replacing the ECM.
Did you complete the replacement? —
Go to Step 11 —
11 1 Use Tech 2 to clear the DTCs.
2 Turn OFF the ignition for 30 seconds.
3 Start the engine.
4 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 1 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? —
Go to the
appropriate DTC Table in this Section System OK
When all diagnosis and repairs are completed, clear all DTCs and verify correct operation
7.61 DTC U0001
DTC Descriptor
This diagnostic procedure supports DTC U0001 – No Communication with CAN-Bus (High Speed).
Circuit Description
The engine control module (ECM) communicates directly with the control modules connected to the GM LAN serial data
communication circuit through the GM LAN protocol.
However, the immobiliser control unit (ICU) communicates with the ECM using the keyword 2000 protocol. Since the GM
LAN and keyword 2000 protocols are not compatible, a powertrain interface module (PIM) is integrated into the serial
data system to serve as a gateway. This gateway allows communication between the two protocols. Refer to 6E1
Powertrain Interface Module – V6 for further information on the GM LAN serial data communication circuit.
DTC U0001 sets if the ECM detects a fault condition in the serial data communication circuit.
Conditions for Running the DTC
DTC U0001 runs continuously when the following conditions are met:
The ignition voltage is 10.0 – 16.0 V.
The vehicle power mode requires serial data communication.

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Engine Management – V6 – Diagnostics Page 6C1-2–219

Conditions for Setting the DTC
The ECM detects a specified number of transmitted messages are not valid.
Conditions for Clearing the DTC
The Serial Data Communication Circuit DTCs are Type ‘C’ DTCs. Refer to 1.4 Diagnostic Trouble Codes in this
Section, for action taken when a Type ‘C’ DTC sets and conditions for clearing Type ‘C’ DTCs.
Additional Information
• Refer to 6C1-1 Engine Management – V6 – General Information for details of the ECM operation.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.
Test Description
The following number refers to the step numbers in the diagnostic table:
1 The following tests are included in the Diagnostic System Check.
• Tests the integrity of the GM LAN serial data communication circuit.
• Tests for fault conditions on the vehicle immobiliser system stored in the ICU.
DTC U0001 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.4 Diagnostic
System Check in this Section
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC U0001 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 4 —
4 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does DTC U0001 fail this ignition cycle? Go to Step 2 Go to Step 5
5 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.

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Engine Management – V6 – Diagnostics Page 6C1-2–220

7.62 DTC U0101
DTC Description
This diagnostic procedure supports the following DTC:
• DTC U0101 – CAN-Bus No Communication W ith TCM (Transmission Control Module)
Circuit Description
The Engine Control Module (ECM) communicates directly with the control modules connected to the GM LAN serial data
communication circuit through the GM LAN protocol.
However, the immobiliser control unit (ICU) communicates with the ECM using the keyword 2000 protocol. Since the GM
LAN and keyword 2000 protocols are not compatible, a powertrain interface module (PIM) is integrated into the serial
data system to serve as a gateway. This gateway allows communication between the two protocols. Refer to 6E1
Powertrain Interface Module – V6 for further information on the GM LAN serial data communication circuit.
A serial data communication circuit – TCM DTC sets if the ECM detects an invalid signal from the TCM.
Conditions for Running the DTC
DTC U0101 runs continuously when the following conditions are met:
• The ignition is on for longer than 3 seconds.
• The ignition voltage is 10.0 – 16.0 V.
Conditions for Setting the DTC
The ECM did not receive a valid signal from the TCM within the specified time frame.
Conditions for Clearing the DTC
This Serial Data Communication Circuit DTC is a Type C DTC. Refer to 1.4 Diagnostic Trouble Codes in this Section,
for action taken when a Type C DTC sets and the conditions required for clearing Type C DTCs.
Additional Information
• Refer to 6C1-1 Engine Management – V6 – General Information for details of the ECM operation.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.
Test Description
The following number refers to the step numbers in the diagnostic table:
1 The following tests are included in the Diagnostic System Check.
• Tests the integrity of the GM LAN serial data communication circuit.
• Tests for fault conditions on the vehicle immobiliser system stored in the ICU.
DTC P0864 and U0101 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.4 Diagnostic
System Check in this Section

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ISUZU KB P190 2007

Engine Management – V6 – Diagnostics Page 6C1-2–221

Step Action Yes No
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC U0101 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 Using Tech 2, attempt to communicate with the PIM.
Does the PIM failed to communicate? Refer to the 6E1
Powertrain Interface Module – V6 Go to Step 4
4 Are DTCs also set in the PIM? Refer to 6E1
Powertrain Interface Module – V6 Go to Step 5
5 Are DTCs that may trigger a fault condition in the serial data
communication circuit also set in the TCM? Refer to 7C2
Automatic
Transmission –
4L60E – Electrical Diagnosis Go to Step 6
6 Replace the TCM, refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Servicing.
W as the repair completed? Go to Step 7 —
7 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does any of the serial data communication circuit – TCM DTCs fail
this ignition cycle? Go to Step 2 Go to Step 8
8 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.
7.63 DTC U0155 or U0423
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC U0155 – CAN-Bus No Communication W ith Gateway
• DTC U0423 – CAN-Bus Invalid Data From Gateway
Circuit Description
The Engine Control Module (ECM) communicates directly with the control modules connected to the GM LAN serial data
communication circuit through the GM LAN protocol.
However, the immobiliser control unit (ICU) communicates with the ECM using the keyword 2000 protocol. Since the GM
LAN and keyword 2000 protocols are not compatible, a powertrain interface module (PIM) is integrated into the serial
data system to serve as a gateway. This gateway allows communication between the two protocols. Refer to 6E1
Powertrain Interface Module – V6 for further information on the GM LAN serial data communication circuit
A PIM serial data communication circuit DTC sets if the ECM detects an invalid signal from the PIM.
Conditions for Running the DTC
DTCs U0155 and U0423 run continuously when the following conditions are met:
• The engine is running.

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ISUZU KB P190 2007

Engine Management – V6 – Diagnostics Page 6C1-2–222

• The ignition voltage is 10.0 – 16.0 V.
Conditions for Setting the DTC
The ECM did not receive a valid signal from the PIM within the specified time frame.
Conditions for Clearing the DTC
The PIM serial data communication circuit DTCs are Type C DTCs. Refer to 1.4 Diagnostic Trouble Codes in this
Section, for action taken when a Type C DTC sets and conditions for clearing Type C DTCs.
Additional Information
• Refer to 6C1-1 Engine Management – V6 – General Information for details of the ECM operation.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.
Test Description
The following number refers to the step numbers in the diagnostic table:
1 The following tests are included in the Diagnostic System Check.
• Tests the integrity of the GM LAN serial data communication circuit.
• Tests for fault conditions on the vehicle immobiliser system stored in the ICU.
DTC U0155 or U0423 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.4 Diagnostic
System Check in this Section
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC U0155, or U0423 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this Section
3 Replace the PIM. Refer to 6E1 Powertrain Interface Module – V6.
W as the repair completed? Go to Step 4 —
4 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does any of the PIM serial data communication circuit DTCs fail this
ignition cycle? Go to Step 2 Go to Step 5
5 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.

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Engine Management – V6 – Diagnostics Page 6C1-2–225

F5: EVAP Purge Solenoid
F6: Engine Speed Control
F7: Starter Relay Test
F8: Fuel Injector Balance
F5: Additional Functions
W hen this selection is made from the Tech 2 screen, an additional two choices are provided:
F0: System Identification: In this mode, Tech 2 will display the engine identification screen.
F1: Security Information: W hen selected, this mode displays various engine management data parameters relating to the security system.
F6: Programming
W ithin this selection, there are five programming selections available:
F0: Immobiliser Link to ECM/PIM
F1: Reset ECU
F2: Fuel Trim Reset
F3: Reset Engine Oil Life
F4: Throttle Body Relearn

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Engine Management – V6 – Diagnostics Page 6C1-2–245

Starter Motor Relay Test
The engine will crank and start during the
starter relay test.
Allows the Technician to turn the starter relay ‘On’, thereby activating the starter motor and cranking the engine.
Preconditions: Apply park brake, firmly apply foot brake, ignition ‘On’, engine ‘Off’, transmission in Park or Neutral.
Fuel Injector Balance
This test allows the Technician to check the fuel flow through each injector when the engine is not running. The
sequence of events are:
1 Install a fuel pressure gauge to the fuel rail.
2 Select ‘Fuel Injector Balance Test’, from the ‘Actuator Test’ menu on Tech 2
3 Activate the fuel injector balance test with Tech 2. This action activates the fuel pump and stabilises the fuel delivery system fuel pressure. The fuel pump is then turned off.
4 Note the stabilised fuel rail pressure.
5 W hen the pump is turned ‘Off’, the injector is activated for a pre-determined time.
6 The fuel pressure drop is then noted from the fuel pressure gauge.
NOTE
For a detailed procedure and analysis of fuel
injector condition, refer to 5.3 Fuel Injector
Balance Test.
8.7 Programming
F0: ICU Link to ECM/PIM : Should the ECM, PIM or ICU be replaced, the modules must be security linked to
each other. If this linking procedure is not performed, the vehicle will not crank nor run. For additional
information relating to Tech 2 and the linking procedure, refer to 11A – Immobiliser.
NOTE
After an ECU reset, the ignition switch must be
turned Off for at least 10 seconds and then
turned On for at least one minute, before
attempting communication between Tech 2 and
the ECU.
Preconditions: TIS approval (TIS 2000 Security Access) must be obtained, the four digit security number
entered into Tech 2 and the theft deterrent system disarmed. Then the ignition must be turned ‘On’, using a
programmed remote coded key.
F1: Reset ECU : This function erases the security link between the Engine Control Module (ECM) and the
Powertrain Interface Modules (PIM). If this procedure is performed, the engine will not crank nor run. A ICU
Link to ECM/PIM procedure will need to be performed. For additional information relating to the ICU Link to
ECM/PIM procedure, refer to 11A – Immobiliser.

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