Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 70

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

6E–275

8

Using the DVM and check the exhaust throttle VSV 1
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. Remove the exhaust throttle VSV 1 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. Remove the exhaust throttle VSV 1 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 11

9

Substitute a known good exhaust throttle VSV 1 and
recheck. 
Was the problem solved?

—

Go to Step 10

Go to Step 11

10

Replace the exhaust throttle VSV 1. 
Is the action complete?

—

Verify repair

—

11

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 12

Step

Action

Value(s)

Yes

No

2

40

C-13

2

40

C-13

C-56

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

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

—

Step

Action

Value(s)

Yes

No

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

6E–277

Diagnostic Trouble Code (DTC) P1576 (Symptom Code 8) (Flash Code 71) 

Exhaust Throttle VSV 1 Circuit Voltage High

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 P1576 (Symptom Code 8) 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 P1576 (Symptom Code 8) stored in this
ignition cycle?

—

Go to Step 4

Refer to 

Diagnostic Aids

4

Check for poor/faulty connection at the exhaust
throttle VSV 1 or ECM 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 exhaust throttle VSV 1.

1. Ignition “Off”,  engine “Off”. 

2. Disconnect the exhaust throttle VSV 1 connector. 

3. Measure the resistance of EGR EVRV solenoid

coil. 

Does the tester indicate standard resistance?   

Approximately 

40

Ω at 20°C

Go  to Step 6

Go to Step 8

40

C-56

C-13

1

2

1

2

VSV-1

6E–278

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

6

Using the DVM and check the exhaust throttle VSV 1
circuit. 

1. Ignition “Off”, engine “Off”. 

2. Remove the exhaust throttle VSV 1 connector and

ECM connector. 

3. Check the circuit for short to voltage circuit. 

Was the DVM indicated specified value?

No continuity

Go to Step 10

Go to Step 7

7

Repair the short to voltage circuit. 
Is the action complete?

—

Verify repair

—

8

Substitute a known good exhaust throttle VSV 1 and
recheck. 
Was the problem solved?

—

Go to Step 9

Go to Step 10

9

Replace the exhaust throttle VSV 1. 
Is the action complete?

—

Verify repair

—

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

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

—

Step

Action

Value(s)

Yes

No

2

1

C-13