Isuzu KB P190. Manual - part 467

ENGINE CONTROL SYSTEM (4JK1/4JJ1)   6E-251

Circuit/ System Testing DTC P156B

5

1.

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

—

6E-252   ENGINE CONTROL SYSTEM (4JK1/4JJ1)

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.

Observe the Battery Voltage parameter with a
scan tool.

Does the scan tool indicate less than the specified
value?

16.0 volts

Go to Step 7

Go to Step 4

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

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

—

6E-254   ENGINE CONTROL SYSTEM (4JK1/4JJ1)

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.

5.

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 7

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