Isuzu KB P190. Manual - part 479

ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-299

Turn OFF the ignition.

Disconnect the TCM harness connector.

Connect a test lamp between the accelerator
pedal position (APP) signal circuit of the TCM
harness connector (pin 16 of C-94) and a
known good ground.

Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

—

Go to Step 4

Go to Step 5

Test the signal circuit between the ECM (pin
56 of C-58) and the TCM (pin 16 of C-94) for a
short to battery or ignition voltage.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 7

Go to Step 6

Important: Replacement TCM must be
programmed.
Replace the TCM. Refer to TCM Replacement.

Did you complete the replacement?

—

Go to Step 7

—

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

Did you complete the replacement?

—

Go to Step 7

—

Reconnect all previously disconnected
harness connector(s).

Clear the DTCs with a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

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 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

6E-300 ENGINE CONTROL SYSTEM (4JK1/4JJ1)

DTC U0001 or U0101 (Flash Code 84 or 85)

Circuit Description

The ECM, the transmission control module (TCM), the
immobilizer control unit (ICU), the data recording
module (DRM), instrument panel (IP) cluster and scan
tool communicate control and diagnostic information
via a controller area network (CAN) communication
bus. The ECM monitors CAN operational status by
expecting a constant flow of messages from the TCM,
ICU, DRM and IP cluster. If the ECM fails to send or
receive an expected message from the TCM, ICU,
DRM and IP cluster, DTC U0001 or U0101 will set
depending on what communication is lost.

Condition for Running the DTC

• The battery voltage is more than 9 volts.

• The ignition switch is ON.

Condition for Setting the DTC

• The ECM detects that the CAN Bus OFF status.

(DTC U0001)

• The ECM detects that the CAN Bus messages

from the TCM are not being received. (DTC
U0101)

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 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.

Notice:

• If the TCM has DTCs set, clear the DTCs in the

TCM first.

Schematic Reference: Engine Controls Schematics

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

Circuit/ System Testing DTC U0001 or U0101

Step

Action

Value(s)

Yes

Did you perform the Diagnostic System Check -
Engine Controls?

—

Go to Step 2

Go to Diagnostic

System Check -
Engine Controls

Refer to Scan Tool Does Not Communicate with
The CAN Device in this section.

Did you complete the action?

—

Go to Step 3

—

Reconnect all previously disconnected
harness connector(s).

Clear the DTCs with a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

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 4

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-301

DTC U0167 (Flash Code 177)

Circuit Description

The ECM communicates with the immobilizer control
unit (ICU) to execute immobilizer function. The ECM
sends request signal to the ICU. The ECM receives
response signal from the ICU. Both communication
signals are carried out via a controller area network
(CAN) communication bus. If the ECM does not detect
a response signal from the ICU, this DTC will set.

Condition for Setting the DTC

• The ECM does not receive an 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.

• Any communication fault with the ICU may set this

DTC.

Circuit/ System Testing DTC U0167

Step

Action

Value(s)

Yes

Did you perform the Diagnostic System Check -
Engine Controls?

—

Go to Step 2

Go to Diagnostic

System Check -
Engine Controls

Install a scan tool.

Turn OFF the ignition for 30 seconds.

Turn ON the ignition, with the engine OFF.

Monitor the DTC Information with a scan tool.

Is DTC U0001 also set?

—

Go to DTC U0001

Go to Step 3

Attempt to communicate with the immobilizer
control unit (ICU) via the Immobilizer Data table.

Does the scan tool communicate with the ICU?

—

Go to Step 4

Go to Diagnostic

System Check -

Immobilizer

Controls

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 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

—

Clear the DTCs with a scan tool.

Turn OFF the ignition for 30 seconds.

Turn ON the ignition, with the engine OFF.

Did the DTC fail this ignition?

—

Go to Step 2

Go to Step 7

Observe the DTC Information with a scan tool.

Are there any DTCs that you have not diagnosed?

—

Go to DTC List

System OK

6E-302 ENGINE CONTROL SYSTEM (4JK1/4JJ1)

EGR Control System Check

Description

The EGR system recirculates a part of exhaust gas
back into the intake manifold, which results in reducing
NOx emissions. The EGR control system uses an
electronic control system to ensure both driveability
and low emission. A control current from the ECM
operates a solenoid to control the lift amount of EGR
valve. Also, an EGR position sensor is provided at the
rear of the solenoid to feed actual valve lift amount
back to the ECM for more precision control.
The EGR control starts when the conditions for engine
speed, engine coolant temperature, intake air
temperature and barometric pressure are satisfied.
Then, the valve opening is calculated according to the
engine speed, and target fuel injection quantity. Based
on this valve opening, the drive duty of the solenoid is
determined and the valve is driven accordingly. The
intake throttle valve is provided to adequate intake
manifold depression to ensure EGR gas flow.

EGR Control Operation

• The engine coolant temperature (ECT) is between

°C (41°F) and 100°C (212°F).

• The intake air temperature (IAT) is more than 5

°C

(41

°F).

• The barometric pressure (BARO) is more than

90kPa (13psi).

Schematic Reference: Engine Controls Schematics

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

Circuit/ System Testing EGR Control System Check

Step

Action

Value(s)

Yes

Did you perform the Diagnostic System Check -
Engine Controls?

—

Go to Step 2

Go to Diagnostic

System Check -
Engine Controls

Install a scan tool.

Turn OFF the ignition for 30 seconds.

Turn ON the ignition, with the engine OFF.

Monitor the DTC Information with a scan tool.

Are any DTCs set in which the “Action Taken When
the DTC Sets” under that particular code states,
“The ECM inhibits EGR control”?

—

Refer to Applicable

DTC

Go to Step 3

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