2007 ISUZU KB P190 CIRCUIT IMMOBILISER

Engine Management – V6 – Diagnostics Page 6C1-2–140

Circuit Description
The engine control module (ECM), the powertrain interface module (PIM) and the immobiliser control unit (ICU) are
integral parts of the vehicle immobiliser system. The immobiliser system authenticates the security code programmed
into each of these modules to prevent unauthorised vehicle operation. This authentication process includes the following
steps:
1 At predetermined situations, the ICU sends a security code to the PIM.
2 W hen the ignition is switched ON, the PIM receives and compares this security code from the ICU against the security code programmed into the PIM.
3 Once the PIM receives the correct security code from the ICU, it sends a security code to the ECM.
4 The ECM receives and compares this security code from the PIM against the security code programmed into the ECM.
5 The authentication process is complete once the ECM receives the correct security code from the PIM within the specified time frame.
6 The ECM allows normal vehicle operation.
NOTE
If any of these authentication processes fail, the
vehicle will not start and DTCs will set. For further
information on the immobiliser system, refer to
11A Immobiliser.
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
P0513
The ECM receives an incorrect response from the PIM during the immobiliser authentication process.
P0633
An attempt is made to start the engine before the immobiliser function has been programmed into a new PIM.
P1629
The ECM has not received a fuel enable password from the ICU.
P1632
The ECM receives an incorrect response from the PIM during the immobiliser authentication process.
P1677
An attempt is made to start the vehicle after the ECM was reset.
P1678
The ECM does not receive a valid response from the PIM when an attempt is made to start the engine.
P1679
The ECM receives a message from the PIM stating that it can't authenticate to the ICU.

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Engine Management – V6 – Diagnostics Page 6C1-2–141

Conditions for Clearing the DTC
Refer to 1.4 Diagnostic Trouble Codes in this Section, for action taken when a Type B DTC sets and conditions for
clearing Type B DTCs.
Additional Information
• Refer to 6C1-1 Engine Management –V6 – General Information for details of the ECM operation.
• Refer to 11A Immobiliser for the following information:
• ICU link to PIM, and
• Immobiliser System.
• Since a 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.
DTC P0513, P0633, P1629, P1632, P0633, P1677, P1678, P1679 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 setting the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0513, P1629, P1632, P0633, P1677, P1678 or P1679 fail
this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 Using Tech 2, perform the ICU Link to ECM / PIM procedure. Refer to
6E1 Powertrain Interface Module – V6.
Has the linking procedure been performed correctly? Go to Step 7 Go to Step 4
4 Test the Immobiliser system. Refer to 11A Immobiliser.
Has any fault been found and rectified? Go to Step 7 Go to Step 5
5 1 Test all ground circuits of the PIM for a high resistance or an
open circuit fault condition. Refer to 8A Electrical - Body and
Chassis for information on electrical fault diagnosis.
2 Test the PIM ignition supply voltage circuit for a high resistance, open circuit or short to ground fault condition. Refer to 8A
Electrical - Body and Chassis for information on electrical fault
diagnosis.
Has any fault been found and rectified? Go to Step 7 Go to Step 6
6 Replace the PIM. Refer to 6E1 Powertrain Interface Module – V6.
Has the repair been 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.
Do any of the immobiliser DTCs fail this ignition cycle? Go to Step 2 Go to Step 8

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ISUZU KB P190 2007

Engine Management – V6 – Diagnostics Page 6C1-2–151

7.35 DTC P0615, P0616 or P0617
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0615 – Starter Relay Circuit Malfunction
• DTC P0616 – Starter Relay Circuit Low Voltage
• DTC P0617 – Starter Relay Circuit High Voltage
Circuit Description
The engine control relay applies battery voltage to the coil circuit of the starter relay through the ignition circuit. W hen
the ignition switched is turned to the Start position and all the conditions required to enable an engine cranking is met,
the ECM grounds the starter relay control circuit to activate the starter relay. W hen active, the starter relay applies
battery voltage to the starter motor solenoid control circuit to operate the starter motor. Refer to 6D1-2 Starting System –
V6 for information on the cranking system operation.
The ECM monitors the control circuit of the starter relay for conditions that are incorrect for the commanded state. A
starter relay control circuit DTC sets if the ECM detects a fault condition in the starter relay control circuit.
Conditions for Running the DTC
DTCs P0615, P0616 and P0617 run continuously once the following conditions are met:
• The ignition is switched on
• The ignition voltage is 10.0 – 16.0 V.
Conditions for Setting the DTC
The ECM detects a condition that is incorrect for the starter relay commanded state.
Conditions for Clearing the DTC
The starter relay control circuit DTCs are Type C DTCs. Refer to 1.4 Diagnostic Trouble Codes in this Section, for
action taken when Type C DTCs set and conditions for clearing Type C DTCs.
Additional Information
• Refer to 6D1-2 Starting System – V6 for information on the cranking system operation.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• 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.
• 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 number in the diagnostic table:
3 A fault condition in the starting system or immobiliser system may trigger this DTC.
DTC P0615, P0616 or P0617 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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Engine Management – V6 – Diagnostics Page 6C1-2–152

Step Action Yes No
2 1 Switch off the ignition for 30 seconds.
2 Turn the ignition switch to the Start position or operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0615, P0616 and P0617 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 Check for a fault condition in the following systems which can disable
the starting system:
• Starting System, refer to 6D1-2 Starting System – V6.
• Immobiliser System, refer to 11A Immobiliser.
W as any fault found and rectified? Go to Step 10 Go to Step 4
4 1 Remove the starter relay. Refer to 8A Electrical - Body and
Chassis.
2 Connect a test lamp between the ignition circuit of the starter relay and a good ground.
3 Switch on the ignition.
Does the test lamp illuminate when the ignition switch is turned to the
on position? Go to Step 5 Go to Step 6
5 1 Connect a test lamp between the control circuit of the starter
relay and a 12 V.
2 Turn the ignition switch to the Start position and then release it back to the on position.
Does the test lamp turn on when the ignition switch is turned to the
Start position and then turn off when the ignition switch returns to the
on position? Go to Step 8 Go to Step 7
6 Repair the ignition voltage circuit of the starter relay for a high
resistance or open circuit fault condition. Refer to 8A Electrical - Body
and Chassis for information on electrical wiring repair procedures.
W as the repair completed? Go to Step 10
—
7 Test the control circuit of the starter relay for a high resistance, open
circuit, short to ground or a short to voltage fault condition. Refer to
8A Electrical - Body and Chassis for information on electrical fault
diagnosis.
W as any fault found and rectified? Go to Step 10 Go to Step 9
8 Replace the starter relay. Refer to 8A Electrical - Body and Chassis.
W as the repair completed? Go to Step 10
—
9 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 10
—
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 the starter relay control circuit DTCs 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

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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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