Isuzu KB P190. Manual — part 300

6E-166 Engine Control System (4JH1)

DTC P0560 (Symptom Code 1) (Flash Code 35)

Circuit Description
The engine control module (ECM) monitors the system
voltage on the ECM main relay load supply voltage
terminal to make sure that the voltage stays within the
proper range. If the ECM detects an excessively high
system voltage, this DTC will set.
Condition for Setting the DTC

• The ECM detects that the battery voltage feed

circuit voltage is more than 20 volts.

Action Taken When the DTC Sets

• The ECM does not illuminate the malfunction

indicator lamp (MIL) when the diagnostic runs and
fails.

Condition for Clearing the DTC

• A history DTC clears after 40 consecutive driving

cycles without a fault. Or clear with the scan tool.

Diagnostic Aids

• A charging system problem may set this DTC.
• Jump starting the vehicle or a battery charger may

have set this DTC.

DTC P0560 (Symptom Code 1) (Flash Code 35)
Schematic Reference: Engine Controls Schematics &
Starting and Charging Schematics

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 the scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the Diagnostic Trouble Code (DTC)

Information with the scan tool.

Does the DTC fail this ignition?



Go to Step 3

Go to Diagnostic

Aids

3

Was the vehicle recently jump started from 24 volts
system?



Go to Step 8

Go to Step 4

4

1. Start the engine and let idle for 30 seconds.
2. Observe the System Voltage parameter with the

scan tool.

Is the System Voltage parameter less than the
specified value?

16 volts

Go to Diagnostic

Aids

Go to Step 5

5

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 6

Go to Step 7

6

Repair the charging system. Refer to Diagnosis of
The Charging System in the Charging System
Section.
Did you complete the repair?



Go to Step 8



7

Important: Replacement ECM must be
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this section.
Did you complete the replacement?



Go to Step 8



8

1. Reconnect all previously disconnected harness

connector(s).

2. Clear the DTCs with the scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Observe the System Voltage parameter with the

scan tool.

Is the System Voltage parameter less than the
specified value?

16 volts

Go to Step 9

Go to Step 5

9

Observe the DTC Information with the scan tool.
Are there any DTCs that you have not diagnosed?



Go to Diagnostic

Trouble Code (DTC)

List System

OK

Engine Control System (4JH1) 6E-167

DTC P0560 (Symptom Code 2) (Flash Code 35)

Circuit Description
The engine control module (ECM) monitors the system
voltage on the ECM main relay load supply voltage
terminal to make sure that the voltage stays within the
proper range. If the ECM detects an excessively low
system voltage, this DTC will set.
Condition for Setting the DTC

• The ECM detects that the battery voltage feed

circuit voltage is less than 7 volts.

Action Taken When the DTC Sets

• The ECM does not illuminate the malfunction

indicator lamp (MIL) when the diagnostic runs and
fails.

Condition for Clearing the DTC

• A history DTC clears after 40 consecutive driving

cycles without a fault. Or clear with the scan tool.

Diagnostic Aids

• If an intermittent condition is suspected, refer to

Intermittent Conditions in this section.

• A charging system problem may set this DTC.

DTC P0560 (Symptom Code 2) (Flash Code 35)
Schematic Reference: Engine Controls Schematics &
Starting and Charging Schematics
Connector End View Reference: Engine Control
Module (ECM) Connector End Views

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 the scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the Diagnostic Trouble Code (DTC)

Information with the scan tool.

Does the DTC fail this ignition?



Go to Step 3

Go to Diagnostic

Aids

3

1. Start the engine and let idle for 30 seconds.
2. Load the electrical system by turning ON the

headlights, A/C, etc.

3. Observe the System Voltage parameter with the

scan tool.

Is the System Voltage parameter more than the
specified value?

10 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 Step 6

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 8



6

1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent, for a poor connection

and corrosion on the battery voltage feed at the
harness connector of the ECM (pin 3 of C-56
connector).

4. Repair or clean the connection(s) as necessary.
Did you find and correct the condition?



Go to Step 8

Go to Step 7

7

Important: Replacement ECM must be
programmed.
Replace the ECM. Refer to Engine Control Module
(ECM) Replacement in this section.
Did you complete the replacement?



Go to Step 8



6E-168 Engine Control System (4JH1)

Step Action

Value(s)

Yes

No

8

1. Reconnect all previously disconnected harness

connector(s).

2. Clear the DTCs with the scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine.
5. Load the electrical system by turning ON the

headlights, A/C, etc.

6. Observe the System Voltage parameter with the

scan tool.

Is the System Voltage parameter more than the
specified value?

10 volts

Go to Step 9

Go to Step 4

9

Observe the DTC Information with the scan tool.
Are there any DTCs that you have not diagnosed?



Go to Diagnostic

Trouble Code (DTC)

List System

OK

Engine Control System (4JH1) 6E-169

DTC P0560 (Symptom Code A) (Flash Code 35)

Circuit Description
The fuel injection pump control unit (PCU) monitors the
system voltage on the engine control module (ECM)
main relay load supply voltage terminal to make sure
that the voltage stays within the proper range. If the
ECM detects an excessively high or low system voltage,
this DTC will set.
Condition for Setting the DTC

• The PCU battery voltage feed circuit voltage is

less than 4.5 volts or more than 27 volts.

Action Taken When the DTC Sets

• The ECM does not illuminate the malfunction

indicator lamp (MIL) when the diagnostic runs and
fails.

Condition for Clearing the DTC

• A history DTC clears after 40 consecutive driving

cycles without a fault. Or clear with the scan tool.

Diagnostic Aids

• If an intermittent condition is suspected, refer to

Intermittent Conditions in this section.

• A charging system problem may set this DTC.
• Jump starting the vehicle or a battery charger may

have set this DTC.

Notice:

• PCU is part of the fuel injection pump assembly.

DTC P0560 (Symptom Code A) (Flash Code 35)
Schematic Reference: Engine Controls Schematics &
Starting and Charging Schematics
Connector End View Reference: Engine Controls
Connector End Views

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 the scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Monitor the Diagnostic Trouble Code (DTC)

Information with the scan tool.

Is DTC P0560 (Symptom Code 1 or 2) set?



Go to Applicable

DTC

Go to Step 3

3

1. Start the engine and let idle for 30 seconds.
2. Monitor the Diagnostic Trouble Code (DTC)

Information with the scan tool.

Does the DTC fail this ignition?



Go to Step 4

Go to Diagnostic

Aids

4

1. Turn OFF the ignition.
2. Disconnect the fuel injection pump control unit

(PCU) harness connector.

3. Inspect for an intermittent, for poor connections

and corrosion on the voltage feed or ground at
the harness connector of the PCU (pins 6 and 7
of E-6 connector).

4. Repair or clean the connection(s) as necessary.
Did you find and correct the condition?



Go to Step 6

Go to Step 5

5

Important: The fuel injection pump must be timed to
the engine.
Replace the fuel injection pump. Refer to Fuel
Injection Pump Replacement in engine mechanical
section.
Did you complete the replacement?



Go to Step 6

6

1. Reconnect all previously disconnected harness

connector(s).

2. Clear the DTCs with the scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine and let idle for 30 seconds.
5. Monitor the DTC Information with the scan tool.
Did the DTC fail this ignition?



Go to Step 2

Go to Step 7