Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 58

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

6E–227

12

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 13

13

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–228

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

Diagnostic Trouble Code (DTC) P0703 (Symptom Code B) (Flash Code 25) 

Brake Switch 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 P0703 (Symptom Code B) 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 P0703 (Symptom Code B) 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 brake switch 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 brake switch 2. 

1. Ignition “Off”, engine “Off”. 

2. Remove the brake switch connector at the brake

pedal. 

3. Check the brake switch 2. 

Was the DVM indicated specified value?

Pedal is not 

stepped on: 

No continuity

Pedal stepped 

on: Continuity 

Go to Step 6

Replace pedal 

switch and 

verify repair

65

3

2

C-56

C-44

Brake Switch

3

2

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

6E–229

6

Using the DVM and check the brake switch 2 power
supply circuit. 

1. Ignition “On”, engine “Off”. 

2. Remove the brake switch connector from the

brake switch. 

3. Check the circuit for open circuit. 

Was the DVM indicated specified value?

Battery 
voltage

Go to Step 8

Go to Step 7

7

Repair the open circuit between the “ECM Main
Relay” and brake switch 2. 
Is the action complete?

—

Verify repair

—

Step

Action

Value(s)

Yes

No

V

2

C-44

2

1

C-44

X-4

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

8

Using the DVM and check the brake switch 2 circuit. 
Breaker box is available: 

1. Ignition “Off”, engine “Off”. 

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

connected) 

3. Ignition “On”, engine “Off”. 

4. Check the circuit for open or short to voltage

circuit. 

Was the DVM indicated specified value?

Breaker box is not available: 

1. Ignition “On”, engine “Off”. 

2. Back probe the DVM to the brake switch 2 and

check the circuit for open or short to voltage
circuit. 

Was the problem found?

Pedal is not 

stepped on: 

Battery 
voltage

Pedal stepped 

on: Less than 

1V Go 

to 

Step 11

Fixed at battery 

voltage: Go to 

Step 9

Fixed at less 

than 1V: Go to 

Step 10

9

Repair the short to voltage circuit between the brake
switch 2 connector and ECM. 
Is the action complete?

—

Verify repair

—

10

Repair the open circuit between the brake switch 2
connector and ECM. 
Is the action complete?

—

Verify repair

—

Step

Action

Value(s)

Yes

No

65

V

V

3

C-44

65

3

C-56

C-44

65

3

C-56

C-44