Isuzu KB P190. Manual - part 155

BRAKE CONTROL SYSTEM   5A-27 

Actuator Test 

There are 8 different menus available for this test. 

The state of each circuit can be tested by using these 

menus. Especially when DTC cannot be detected, a

faulty circuit can be diagnosed by testing each circuit by

means of these menus. 

Even when DTC has been detected, the circuit tests 

using these menus could help discriminate between a 

mechanical fault and an electrical fault. 

In all cases test condition; Engine stops with the key 

turned to the "ON" position. To be more specific, the

test is conducted with the brake pedal stepped on after

stepping once and releasing. 
 

 
 

 

 
 

RTW75ASH000201

 

Brake Bleed 

Purpose: The purpose of this command is air bleeding 

of brakes line. 

Using the Tech 2 at following operation. 

 

Air Bleeding procedure: 

1. Connect the Tech 2 with the vehicle, and select

"Actuator Test" menus. 

 

2. Select a "Brake Bleed" menu from the "Actuator 

Test" menus. 

 

 
 

 

 

RTW75ASH000301

 

3. According to indication of Tech 2 press the

"Confirm". 

 

 
 

 

 

 

RTW75ASH000401

5A-28   BRAKE CONTROL SYSTEM 

4. Check the EHCU part number. Press the "Confirm".

 

 
 

 

 

RTW75ASH000501

 

5. Check a DTC is not detected. Press the "Confirm". 

 

 
 

 

RTW75ASH000601

 

6. According to indication of Tech 2 press the

"Confirm". 

 

 
 

 

 

RTW75ASH000701

 

7. According to indication of Tech 2 press the

"Confirm". 

 

 
 

 

RTW75ASH000801

 

BRAKE CONTROL SYSTEM   5A-29 

8. According to indication of Tech 2 press the

"Confirm". 

 

 
 

 

 

RTW75ASH000901

 

9. According to indication of Tech 2 press the

"Confirm". 

 

 
 

 

 
 

RTW75ASH001001

 

 

10. According to indication of Tech 2 press the

"Confirm". 

 

 
 

 

 
 

RTW75ASH001101

 
Return Pump Relay Test 

Test condition: Engine stops with the key turned to the

"ON" position. To be more specific, the test is

conducted with the brake pedal stepped on after

stepping once and releasing. 

Test Procedure: 

1. Connect the Tech 2 with the vehicle, and select

"Actuator Test" menus. 

2. Select a " Return Pump Relay Test " menu from the

"Actuator Test" menus. 

The circuit is normal if the pump motor is operated in

accordance with Tech 2 instruction. 

 

Front Left Hold Valve Test 

Purpose: The purpose of this test is to detect brake pipe

and valve line harness wire for incorrect connections

and valve problem. 

This test will help you confirm the result of your repair

service including the removal/ reinstallation of brake

pipe, valve line harness and valve. 

Test conditions: The ignition key is in the "ON" position

with the four wheels lifted up. The brake pedal is

stepped on, released and stepped on again with the

parking brake released. 

 

Test Procedure: 

1. Connect Tech 2 with the vehicle, and select

"Actuator Test" menus. 

2. Select a "Front Left Hold Valve Test" menu from

the "Actuator Test" menus. 

3. Step on the brake pedal. 

 

5A-30   BRAKE CONTROL SYSTEM 

4. Release the brake pedal. 

5. Make sure that the front left hold solenoid valve

"ON" aimed at by Tech 2 and the wheel locked

position are the same. 

If different, check brake pipe, valve line harness wiring 

and hydraulic unit. Repair is needed if abnormality is

found. 
 
Front Left Release Valve Test 

Purpose: The purpose of this test is to detect brake pipe 

and valve line harness wire for incorrect connections and

valve problem. 

This test will help you confirm the result of your repair

service including the removal/ reinstallation of brake

pipe, valve line harness and valve. 

Test conditions: The ignition key is in the "ON" position 

with the four wheels lifted up. The brake pedal is stepped

on, released and stepped on again with the parking

brake released. 

 

Test Procedure: 

1. Connect Tech 2 with the vehicle, and select

"Actuator Test" menus. 

2. Select a "Front Left Release Valve Test" menu from 

the "Actuator Test" menus. 

3. Step on the brake pedal. 

4. Make sure that the front left release solenoid valve

"ON" aimed at by Tech 2 and the wheel released

position are the same. 

If different, check brake pipe, valve line harness wiring 

and hydraulic unit. Repair is needed if abnormality is

found. 
 
Front Right Hold Valve Test 

Purpose: The purpose of this test is to detect brake pipe 

and valve line harness wire for incorrect connections and

valve problem. 

This test will help you confirm the result of your repair

service including the removal/ reinstallation of brake

pipe, valve line harness and valve. 

Test conditions: The ignition key is in the "ON" position 

with the four wheels lifted up. The brake pedal is stepped

on, released and stepped on again with the parking

brake released. 

 

Test Procedure: 

1. Connect Tech 2 with the vehicle, and select

"Actuator Test" menus. 

2. Select a "Front Right Hold Valve Test" menu from 

the "Actuator Test" menus. 

 

 

3. Step on the brake pedal. 

4. Release the brake pedal. 

5. Make sure that the front right hold solenoid valve

"ON" aimed at by Tech 2 and the wheel locked

position are the same. 

If different, check brake pipe, valve line harness wiring

and hydraulic unit. Repair is needed if abnormality is

found. 
 
Front Right Release Valve Test 

Purpose: The purpose of this test is to detect brake pipe

and valve line harness wire for incorrect connections

and valve problem. 

This test will help you confirm the result of your repair

service including the removal/ reinstallation of brake

pipe, valve line harness and valve. 

Test conditions: The ignition key is in the "ON" position

with the four wheels lifted up. The brake pedal is

stepped on, released and stepped on again with the

parking brake released. 

 

Test Procedure: 

1. Connect Tech 2 with the vehicle, and select

"Actuator Test" menus. 

2. Select a "Front Right Release Valve Test" menu

from the "Actuator Test" menus. 

3. Step on the brake pedal. 

4. Make sure that the front right release solenoid valve

"ON" aimed at by Tech 2 and the wheel released

position are the same. 

If different, check brake pipe, valve line harness wiring

and hydraulic unit. Repair is needed if abnormality is

found. 

 

Rear Hold Valve Test 

Purpose: The purpose of this test is to detect brake pipe

and valve line harness wire for incorrect connections

and valve problem. 

This test will help you confirm the result of your repair

service including the removal/ reinstallation of brake

pipe, valve line harness and valve. 

Test conditions: The ignition key is in the "ON" position

with the four wheels lifted up. The brake pedal is

stepped on, released and stepped on again with the

parking brake released. 

 

Test Procedure: 

1. Connect Tech 2 with the vehicle, and select

"Actuator Test" menus.