Isuzu KB P190. 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.