Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 29

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

6E–111

6

Using the DVM and check the MAF sensor signal
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 MAF & IAT sensor connector. 

4. Check the circuit for open, short to sensor ground

or short to ground circuit. 

Was the problem found?

Breaker box is not available: 

1. Ignition “Off”, engine “Off”. 

2. Disconnect the MAF & IAT sensor connector and

ECM connector. 

3. Check the circuit for open, short to sensor ground

or short to ground circuit. 

Was the problem found?

—

Repair faulty 
harness and 

verify repair

Go to Step 7

7

Using the DVM and check the MAF sensor power
supply circuit.

1. Ignition “On”, engine “Off”. 

2. Disconnect the MAF & IAT sensor connector. 

3. Check the circuit for open circuit. 

Was the DVM indicated specified value?

Approximately 

5.0V

Go to Step 9

Go to Step 8

Step

Action

Value(s)

Yes

No

88

5

C-51

5

88

C-51

C-57(B)

V

4

C-51

6E–112

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

8

Repair the open circuit between the ECM and MAF
sensor. 
Was the problem solved?

—

Verify repair

Go to Step 13

9

Using the DVM and check the MAF sensor heater
circuit.

1. Ignition “On”, engine “Off”. 

2. Disconnect the MAF & IAT sensor connector. 

3. Check the circuit for open circuit. 

Was the DVM indicated specified value?

Battery 
voltage

Go to Step 11

Go to Step 10

10

Repair the open circuit between the ECM main relay
and MAF sensor. 
Was the problem solved?

—

Verify repair

Go to Step 11

11

Substitute a known good MAF & IAT sensor assembly
and recheck. 
Was the problem solved?

—

Go to Step 12

Go to Step 13

12

Replace the MAF & IAT sensor assembly. 
Is the action complete?

—

Verify repair

—

13

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 14

14

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

83

4

C-51

C-57(B)

2

V

C-51

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

6E–113

Diagnostic Trouble Code (DTC) P0100 (Symptom Code C) (Flash Code 65) 

Mass Air Flow (MAF) Sensor Output Circuit High Input

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 P0100 (Symptom Code C) 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 P0100 (Symptom Code C) 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 MAF sensor or
ECM connector. If a poor/faulty connection is found,
repair as necessary. 
Was the problem found?

—

Verify repair

Go to Step 5

5

Visually check the MAF sensor. 
Was the problem found? 

—

Go to Step 11

Go to Step 6

92

88

83

2 3

4

5

C-51

C-57(B)

6E–114

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

6

Using the DVM and check the MAF sensor ground
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 MAF sensor connector. 

4. Check the circuit for open circuit. 

Was the problem found?

Breaker box is not available: 

1. Ignition “Off”, engine “Off”. 

2. Disconnect the MAF sensor connector and ECM

connector. 

3. Check the circuit for open circuit. 

Was the problem found?

—

Repair faulty 
harness and 

verify repair

Go to Step 7

7

Using the DVM and check the MAF sensor ground
circuit.

1. Ignition “On”, engine “Off”. 

2. Disconnect the MAF sensor connector . 

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

Was the DVM indicated specified value?

Less than 1V

Go to Step 8

Repair faulty 
harness and 

verify repair

Step

Action

Value(s)

Yes

No

92

3

C-51

3

92

C-51

C-57

3

V

C-51