Isuzu KB P190. Manual - part 454

ENGINE CONTROL SYSTEM (4JK1/4JJ1)   6E-199

5

1.

Test the control circuit between the ECM (pin
35 of C-58) and the relay (pin 3 of X-7) for a
short to ground.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 9

Go to Step 8

6

1.

Test the control circuit between the ECM (pin
35 of C-58) and the relay (pin 3 of X-7) for a
short to battery or ignition voltage.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 9

Go to Step 8

7

Replace the starter cut relay.

Did you complete the replacement?

—

Go to Step 9

—

8

Important: Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.

Did you complete the replacement?

—

Go to Step 9

—

9

1.

Reconnect all previously disconnected relay
or harness connector(s).

2.

Clear the DTCs with a scan tool.

3.

Turn OFF the ignition for 30 seconds.

4.

Turn ON the ignition for 10 seconds.

5.

Start the engine.

Did the DTC fail this ignition?

—

Go to Step 2

Go to Step 10

10

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

6E-200   ENGINE CONTROL SYSTEM (4JK1/4JJ1)

DTC P0633 (Flash Code 176)

Circuit Description

The electronically erasable & programmable read only
memory (EEPROM) memorizes immobilizer security
information for communication with the immobilizer
control unit (ICU) and enabling the engine to start. If the
ECM detects immobilizer security information are not
programmed into the ECM, this DTC will set.

Condition for Setting the DTC

• The ECM detects that the immobilizer security

information is not programmed.

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

• Non-programmed ECM sets this DTC.

Circuit/ System Testing DTC P0633

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.

Does the DTC fail this ignition?

—

Go to Step 3

Go to Diagnostic 

Aids

3

Program immobilizer security information into the
ECM. Refer to Resetting and Programming
Guidelines in immobilizer section.

Did you complete the programming?

—

Go to Step 4

—

4

1.

Clear the DTCs with a scan tool.

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 3

Go to Step 5

5

Observe the DTC Information with a scan tool.

Are there any DTCs that you have not diagnosed?

—

Go to DTC List

System OK

ENGINE CONTROL SYSTEM (4JK1/4JJ1)   6E-201

DTC P0638 (Flash Code 61)

Circuit Description

The ECM controls the intake throttle valve opening
based on the engine running condition and by
controlling the intake throttle solenoid. The intake
throttle valve position is detected by the position
sensor, and relayed to the ECM. If the ECM detects a
variance between the actual intake throttle position and
desired intake throttle position while the intake throttle
solenoid is commanded ON, this DTC will set.

Condition for Running the DTC

• DTCs P0122, P0123, P0698 and P0699 are not

set.

• The battery voltage is between 11 to 16 volts.

• The ignition switch is ON.

• The intake throttle solenoid commanded ON.

• The desired intake throttle position is stable.

Condition for Setting the DTC

• The ECM detects that the difference between the

actual and the desired intake throttle position is
more than 10% for 5 seconds.

Action Taken When the DTC Sets

• 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.

• The ECM limits fuel injection quantity.

• The ECM inhibits pilot injection.

• The ECM inhibits EGR control.

• The ECM inhibits cruise control.

Condition for Clearing the DTC

• Refer to DTC Type Definitions for Condition for

Clearing the MIL/ DTC - Type A.

Diagnostic Aids

• If an intermittent condition is suspected, refer to

Intermittent Conditions in this section.

• A sticking or intermittently sticking intake throttle

valve may set this DTC.

• A sticking intake throttle valve at full closed

position will cause engine starting problem.

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views

Circuit/ System Testing DTC P0638

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.

Start the engine.

4.

Monitor the DTC Information with a scan tool.

Is DTC P0122, P0123, P2100, P2101 or P2103
also set?

—

Go to Applicable 

DTC

Go to Step 3

3

1.

Perform the Intake Throttle Solenoid Control
with a scan tool several times.

2.

Command the Desired Intake Throttle Position
Increase and Decrease while observing the
Intake Throttle Position.

Does the Intake Throttle Position parameter follow
within the specified value quick enough (compare
with a similar unit if available)?

± 5%

Go to Diagnostic 

Aids

Go to Step 4

6E-202   ENGINE CONTROL SYSTEM (4JK1/4JJ1)

4

1.

Remove the intake duct that is connected to
the intake throttle valve.

2.

Inspect the intake throttle valve for the
following conditions:

• Restricted intake throttle valve by foreign

materials

• Excessive deposits at throttle bore

• Bent butterfly valve

Notice: Replace the intake throttle valve if there is
any sticking.

3.

Repair or replace as necessary.

Did you find and correct the condition?

—

Go to Step 7

Go to Step 5

5

1.

Turn OFF the ignition.

2.

Disconnect the intake throttle valve harness
connector.

3.

Inspect for an intermittent, for poor
connections and corrosion at the harness
connector of the intake throttle valve (pins 1,
2, 3, 5 and 6 of E-38).

4.

Disconnect the ECM harness connector.

5.

Inspect for an intermittent, for poor
connections and corrosion at the harness
connector of the ECM (pins 35, 36, 55, 56 and
57 of E-90).

6.

Test for high resistance on each circuit.

7.

Repair the connection(s) or circuit(s) as
necessary.

Did you find and correct the condition?

—

Go to Step 7

Go to Step 6

6

Replace the intake throttle valve. Refer to Intake
Throttle Valve Replacement.

Did you complete the replacement?

—

Go to Step 7

—

7

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 8

8

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