Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 39

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

6E–151

7

Using the DVM and check the CKP sensor output
circuit. 
Breaker box is available: 

1. Ignition “Off”, engine “Off”. 

2. Install the breaker box as type A. (ECM

disconnected) Ref. Page 6E-81

3. Disconnect the PSG (pump control unit)

connector. 

4. Check the circuit for open or short to ground

circuit. 

Was the problem found?

Breaker box is not available: 

1. Ignition “Off”, engine “Off”. 

2. Disconnect the ECM connector. 

3. Disconnect the PSG (pump control unit)

connector. 

4. Check the circuit for open or short to ground

circuit. 

Was the problem found?

—

Repair faulty 
harness and 

verify repair

Go to Step 8

8

Using the DVM and check the CKP sensor output
circuit.

1. Ignition “On”, engine “Off”. 

2. Disconnect the PSG (pump control unit)

connector. 

3. Check the circuit for short to power supply circuit. 

Was the DVM indicated specified value?

Less than 1V

Go to Step 9

Repair faulty 
harness and 

verify repair

Step

Action

Value(s)

Yes

No

91

8

E-6

91

8

C-57(B)

E-6

8

V

E-6

6E–152

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

9

Check any accessory parts which may cause electric
interference or magnetic interference. 
Was the problem found?

—

Remove the 

accessory parts 
and verify repair

Go to Step 10

10

Is the ECM programmed with the latest software
release? 
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”. 
Was the problem solved?

—

Verify repair

Go to Step 11

11

Substitute a known good ECM and recheck. 
Was the problem solved? 
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual. 
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobiliser System-ECM replacement” for
the ECM/Immobiliser linking procedure. 

—

Go to Step 12

Go to Step 13

12

Replace the ECM. 
Is the action complete? 
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual. 
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobiliser System-ECM replacement” for
the ECM/Immobiliser linking procedure.

—

Verify repair

—

13

Replace the injection pump assembly. 
Is the action complete?

—

Verify repair

—

Step

Action

Value(s)

Yes

No

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

6E–153

Diagnostic Trouble Code (DTC) P0251 (Symptom Code 9) (Flash Code 53) 

Injection Pump 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 P0251 (Symptom Code 9) 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 P0251 (Symptom Code 9) stored in this
ignition cycle?

—

Go to Step 4

Refer to 

Diagnostic Aids

4

Replace the injection pump assembly. 
Is the action complete?

—

Verify repair

—

6E–154

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

Diagnostic Trouble Code (DTC) P0251 (Symptom Code A) (Flash Code 53) 

Injection Pump 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 P0251 (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 P0251 (Symptom Code A) stored in this
ignition cycle?

—

Go to Step 4

Refer to 

Diagnostic Aids

4

Replace the injection pump assembly. 
Is the action complete?

—

Verify repair

—