Isuzu KB P190. Service manual — part 927

Powertrain Interface Module – V6

Page 6E1–47

signal voltage input into serial data, which is used by the engine control module (ECM) to enable or disable the cruise
control system, and by the instrument cluster to display cruise control status.

Additional Information

•

Refer to 8C Cruise Control – HFV6 for the following information:

•

Cruise control switch description, operation and inspection procedures, and

•

Cruise control wiring diagram.

•

Refer to 6 Wiring Diagram and Connector for the following information:

•

PIM connector illustration and terminal assignment, and

•

PIM wiring diagram.

•

For intermittent fault conditions, refer to

Intermittent Fault Conditions.

•

Since fault conditions 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.

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

The PIM detects the cruise control on / off function of the cruise control on/off switch is in the ON position for 120
seconds or more.

Action Taken When the DTC Sets

When the DTC sets, there is no warning lamp displayed on the instrument cluster.

If the cruise control is active at the time the DTC sets, the PIM will disable cruise control.

Conditions for Clearing the DTC

Refer to 4.1

Diagnostic General Descriptions for information on the conditions for clearing DTCs.

N O T E

If the fault is not evident for greater than 120
seconds, the DTC will become a history DTC and
cruise control can be resumed.

Test Description

The following numbers refer to the step numbers in the diagnostic table:

2

This step tests the cruise control on / off switch using Tech 2.

6

This step tests the cruise control on / off switch signal circuit.

Powertrain Interface Module – V6

Page 6E1–48

DTC B3794 Diagnostic Table

Step Action

Yes

No

1

Has the Diagnostic System Check been performed?

Go to Step 2

Refer to

7.2 Diagnostic

System Check

2

Using Tech 2, view the cruise control on / off switch status parameter
in the PIM data list.

Does Tech 2 display Active?

Go to Step 4

Go to Step 3

3

1

Switch off the ignition for 10 seconds.

2

Operate the vehicle within the conditions for setting DTC B3794.

3

Using Tech 2, select the DTC display function.

Does DTC B3794 fail this ignition cycle?

Go to Step 4

Refer to

Additional

Information in this

Section

4

1

Disconnect connector B-67 from the cruise control on/off switch.

2

Using Tech 2, view the cruise control on / off switch status
parameter in the PIM data list.

Does Tech 2 display Active?

Go to Step 6

Go to Step 5

5

Replace the cruise control on/off switch, refer to 8C Cruise Control –
HFV6.

Has the repair been completed?

Go to Step 8

—

6

Test the cruise control on / off switch signal circuit for a short to
voltage. Refer to 8A Electrical - Body and Chassis for information on
electrical fault diagnosis.

Has any fault been found and rectified?

Go to Step 8

Go to Step 7

7

Replace the PIM. Refer to 11.2

Powertrain Interface Module.

Has the repair been completed?

Go to Step 8

—

8

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 B3794 fail this ignition cycle?

Go to Step 2

Go to Step 9

9

Using Tech 2, select the DTC display function.

Does Tech 2 display any DTCs?

Go to the

appropriate DTC

Table

System OK

When all diagnosis and repairs are completed, clear all DTCs and check the system for correct operation.

Powertrain Interface Module – V6

Page 6E1–49

9.11 DTC B3902 – Immobiliser Malfunction

DTC Descriptors

This diagnostic procedure supports DTC B3902 – Immobiliser Malfunction.

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

When 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.

N O T E

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

B3902

Ignition set to the ON position.

Conditions for Clearing the DTC

Refer to 4.1 Diagnostic General Descriptions for information on the conditions for clearing DTCs.

Additional Information

•

Refer to 6C1-1 Engine Management –V6 – General Information for details of the ECM operation.

•

Refer to 11A Immobiliser for immobiliser system information:

•

Refer to 12.4

Immobiliser Link to ECM / PIM for immobiliser link to ECM / PIM.

•

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

Intermittent Fault Conditions in this section.

Powertrain Interface Module – V6

Page 6E1–50

•

To assist diagnosis, refer to 6

Wiring Diagram and Connector Chart for the system wiring diagram and

connector charts in this section.

DTC B3902 Diagnostic Table

Step Action

Yes

No

1

Has the Diagnostic System Check been performed?

Go to Step 2

Refer to

7.2 Diagnostic

System Check

2

Using Tech 2, perform the ICU ID check procedure.

Is the ID number displayed by Tech 2?

Go to Step 3

Go to Step 5

3

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 B3902 fail this ignition cycle?

Go to Step 4

Refer to

Additional

Information in this

Section

4

Test the Immobiliser system. Refer to 11A Immobiliser.

Has any fault been found and rectified?

Go to Step 8

Go to Step 7

5

1

Test all ground circuits of the ICU 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 ICU 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 8

Go to Step 6

6

Replace the ICU. Refer to 11A Immobiliser.

Was the repair completed?

Go to Step 8

—

7

Replace the PIM. Refer to 11.2

Powertrain Interface Module.

Was the repair completed?

Go to Step 8

—

8

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 9

9

Using Tech 2, select the DTC display function.

Does Tech 2 display any DTCs?

Go to the

appropriate DTC

Table System

OK

When all diagnosis and repairs are completed, clear all DTCs and check the system for correct operation.

9.12 DTC P0318 – Vertical Acceleration

Sensor

DTC Description

This diagnostic procedure supports the Vertical Acceleration Sensor (VAS).

Circuit Description

The vertical acceleration sensor monitors vertical movement of the vehicle. The powertrain interface module (PIM)
converts the signal voltage input into serial data, which is used by.