Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 62

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

6E–243

9

Using the DVM and check the TPS signal circuit.

1. Ignition “On”, engine “Off”. 

2. Disconnect the TPS connector. 

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

Was the DVM indicated specified value?

Less than 1V

Go to Step 10

Repair faulty 
harness and 

verify repair

10

Using the DVM and check the TPS ground circuit.

1. Ignition “On”, engine “Off”. 

2. Disconnect the TPS 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

Step

Action

Value(s)

Yes

No

V

2

4JA1-TC

C-93

4JH1-TC

E-7

V

1

4JA1-TC

C-93

4JH1-TC

E-7

6E–244

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

11

Using the DVM and check the TPS 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 TPS 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 TPS connector and ECM

connector. 

3. Check the circuit for open circuit. 

Was the problem found?

—

Repair faulty 
harness and 

verify repair

Go to Step 14

12

Substitute a known good TPS and recheck. 
Was the problem solved?

—

Go to Step 13

Go to Step 14

13

Replace the TPS. 
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 14

Step

Action

Value(s)

Yes

No

49

1

4JA1-TC

C-93

4JH1-TC

E-7

49

1

C-56

4JA1-TC

C-93

4JH1-TC

E-7

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

6E–245

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

6E–246

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

Diagnostic Trouble Code (DTC) P1120 (Symptom Code 7) (Flash Code 21) 

Pedal/Throttle Position Sensor Voltage Supply 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 P1120 (Symptom Code 7) 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 P1120 (Symptom Code 7) 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 TPS 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 TPS. 
Was the problem found? 

—

Go to Step 8

Go to Step 6

49

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57

2 3

1

C-56

4JA1-TC

C-93

4JH1-TC

E-7