Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 33

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

6E–127

9

Repair the short to voltage circuit between the ECM
and ECT sensor. 
Was the problem solved?

—

Verify repair

Go to Step 14

10

Using the DVM and check the ECT sensor ground
circuit.

1. Ignition “On”, engine “Off”. 

2. Disconnect the ECT sensor connector. 

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

Was the DVM indicated specified value?

Less than 1V

Go to Step 11

Repair faulty 
harness and 

verify repair

11

Using the DVM and check the ECT 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 ECT 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 ECT sensor connector ECM

connector. 

3. Check the circuit for open circuit. 

Was the problem found?

—

Repair faulty 
harness and 

verify repair

Go to Step 14

Step

Action

Value(s)

Yes

No

89

1

E-41

C-57(B)

2

V

E-41

93

2

E-41

2

93

E-41

C-57

6E–128

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

12

Substitute a known good ECT sensor assembly and
recheck. 
Was the problem solved?

—

Go to Step 13

Go to Step 14

13

Replace the ECT sensor. 
Is the action complete?

—

Verify repair

—

14

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 15

15

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–129

Diagnostic Trouble Code (DTC) P0115 (Symptom Code 2) (Flash Code 14) 

Engine Coolant Temperature Sensor Circuit Low 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 P0115 (Symptom Code 2) 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 P0115 (Symptom Code 2) 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 ECT 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 ECT sensor. 
Was the problem found? 

—

Go to Step 8

Go to Step 6

93

2

1

89

E-41

C-57(B)

6E–130

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

6

Using the DVM and check the ECT sensor.

1. Ignition “Off”,  engine “Off”. 

2. Disconnect ECT sensor connector. 

3. Measure the resistance of ECT sensor. 

Does the tester indicate standard resistance as shown
in the following table? 

Standard 

resistance

Go to Step 7

Go to Step 8

Step

Action

Value(s)

Yes

No

Temperature (°C)

Resistance (

Ω) (Approximately)

-30

27500

-20

16100

0

5760

20

2370

40

1080

60

537

80

290

100

161

120

95

1

2

ECT Sensor

1

2