Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 53

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

6E–207

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

System Voltage Malfunction (PSG)

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to Step 2

Go to On Board 

Diagnostic 

(OBD) System 

Check

2

1. Connect the Tech 2. 

2. Review and record the failure information. 

3. Select “F0: Read DTC Infor As Stored By ECU” in

“F0: Diagnostic Trouble Codes”. 

Is the DTC P0560 (Symptom Code A) stored as
“Present Failure”?

—

Go to Step 3

Refer to 

Diagnostic Aids 

and Go to Step 

3

3

1. Using the Tech 2, ignition “On” and engine “Off”. 

2. Select  “F1: Clear DTC Information” in “F0:

Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information. 

3. Operate the vehicle and monitor the “F0: Read

DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”. 

Was the DTC P0560 (Symptom Code A) stored in this
ignition cycle?

—

Go to Step 4

Refer to 

Diagnostic Aids 

and Go to Step 

4

4

Check for poor/faulty connection at the PSG (pump
control unit) connector. If a poor/faulty connection is
found, repair as necessary. 
Was the problem found?

—

Verify repair

Go to Step 5

5

Using the DVM and check the PSG (pump control
unit) power supply circuit.

1. Ignition “On”, engine “Off”. 

2. Disconnect the PSG (pump control unit)

connector. 

3. Check the PSG (pump control unit) power supply

circuit. 

Was the DVM indicated specified value?

10 - 14V

Go to Step 7

Go to Step 6

6

7

E-6

6

7

V

E-6

6E–208

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

6

Check for poor/faulty connection of the PSG (pump
control unit) ground at the cylinder body. If a poor/
faulty connection is found, repair as necessary. 
Was the problem found?

—

Verify repair

Go to Step 7

7

Replace the injection pump assembly. 
Is the action complete?

—

Verify repair

—

Step

Action

Value(s)

Yes

No

E-10

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

6E–209

DIAGNOSTIC TROUBLE CODE (DTC) P0561 (SYMPTOM CODE A) 

(FLASH CODE 18) SYSTEM VOLTAGE CIRCUIT MALFUNCTION

DIAGNOSTIC TROUBLE CODE (DTC) P0561 (SYMPTOM CODE B) 

(FLASH CODE 18) SYSTEM VOLTAGE CIRCUIT MALFUNCTION

Condition for setting the DTC and action taken when the DTC sets

Circuit Description

The ECM monitors the ignition switch signal on the feed
terminal to the ECM. If the ignition switch signal with
malfunction, DTC P0561 (Symptom Code A) or DTC

P0561 (Symptom Code B) will be stored.

Diagnostic Aids

An intermittent may be caused by the following:

Flash 

Code

Code

Symptom 

Code

MIL

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

18

P0561

A

OFF

System Voltage Circuit Mal-
function

The ECM recognized ignition 
switch turn off signal during 
ECM is activated.

ECM stops engine.

B

ON

System Voltage Circuit Mal-
function

Ignition switch circuit is mal-
function.

Battery
Voltage

Battery
Voltage

ECM
Main Relay

Stop
Light
10A

Injection
Pump

Stop
Lamp

IC

IC

CPU

0.5
BLU/
BLK

58

2.0
BLU/
RED

0.5
BLU/
RED

3

0.5
WHT/
BLK

65

0.85
RED

0.85
RED

0.85
GRN

30

0.5
BLU/
RED
63

0.5
YEL

31

0.5
RED/
BLK

0.5
BLU/
RED

0.5
BLU/
RED

0.85
WHT

0.5
WHT/
RED

0.5
RED/
GRN

Clutch
SW

Resister

Neutral
SW

87

0.5
BLU/
YEL

39

Brake
SW

M/T

A/T

Inhibitor
SW

Ignition
SW

Back,
Turn
15A

Engine
15A

µP

N

P

Engine
Control
Module
(ECM)

Batt

Batt

6E–210

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

• Poor connections.

• Misrouted harness.

• Rubbed through wire insulation.

• Broken wire inside the insulation.
Check for the following conditions:

• Poor connection at ECM-Inspect harness connectors

for backed out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and
poor terminal to wire connection.

• Damaged harness-Inspect the wiring harness for

damage. If the harness appears to be OK, observe
the  “Ignition Status” display on the Tech2 while
moving connectors and wiring harness related to the
sensor.

Diagnostic Trouble Code (DTC) P0561 (Symptom Code A) (Flash Code 18) 

System Voltage Circuit Malfunction

Diagnostic Trouble Code (DTC) P0561 (Symptom Code B) (Flash Code 18) 

System Voltage Circuit Malfunction

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to Step 2

Go to On Board 

Diagnostic 

(OBD) System 

Check

2

1. Connect the Tech 2. 

2. Review and record the failure information. 

3. Select “F0: Read DTC Infor As Stored By ECU” in

“F0: Diagnostic Trouble Codes”. 

Is the DTC P0561 (Symptom Code A) or P0561
(Symptom Code B) stored as “Present Failure”?

—

Go to Step 3

Refer to 

Diagnostic Aids 

and Go to Step 

3

3

1. Using the Tech 2, ignition “On” and engine “Off”. 

2. Select  “F1: Clear DTC Information” in “F0:

Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information. 

3. Operate the vehicle and monitor the “F0: Read

DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”. 

Was the DTC P0561 (Symptom Code A) or P0561
(Symptom Code B)stored in this ignition cycle?

—

Go to Step 4

Refer to 

Diagnostic Aids 

and Go to Step 

4

4

Check the “Engine-2” fuse (10A). 
If the fuse is burnt out, repair as necessary.
Was the problem found?

—

Verify repair

Go to Step 5