2007 ISUZU KB P190 Harness

BRAKE CONTROL SYSTEM 5A-31
2. Select a "Rear 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 rear 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.

Rear 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 repai
r
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 "Rear Release Valve Test" menu from the "Actuator Test" menus.
3. Step on the brake pedal.
4. Make sure that the rear 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.


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

BRAKE CONTROL SYSTEM 5A-41
Wheel Speed Sensor Inspection Procedure
Procedure
1.Ignition "OFF".
2.Disconnect each of the wheel speed sensors.
3.Connect the resistance (50 Ω~100 Ω) as follows.
4.Check the voltage at sensor harness connector.
Note: Voltage measurement is performed in the phase
where the wheel speed sensor is installed in vehicles.

RTW 75AMF000701
Connector Pin-outs
･Front W heel Speed Sensor
1 (+) (+12V)
2 (-) (signal)
･Rear W heel Speed Sensor
1 LH (+) (+12V)
2 LH (-) (signal)
3 RH (+)(+12V)
4 RH (-) (signal)






Output Value
High State 0.7~1.4V (±30%)
Low State 0.4~0.7V (±30%)


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

5A-42 BRAKE CONTROL SYSTEM
Symptom Diagnosis
The symptoms that cannot be indicated by warning
lamp can be divided into the following six categories:
1. ABS works frequently but vehicle does not decelerate.
2. Uneven braking occurs while ABS works.
3. The wheels are locked.

4. Brake pedal feel is abnormal.
5. Braking sound (from EHCU) is heard while not braking.
6. No ABS warning lamp
These are all attributable to problems which cannot be
detected by EHCU self-diagnosis. Use the customer
complaint and a test to determine which symptom is
present.
ABS Works Frequently But Vehicle Does Not Decelerate

Step Action Value(s) Yes No
1 Is braking force distribution normal between front and
rear of vehicle?
- Go to Step 2 Repair brake
parts.
Go to Step 7
2 Are axle parts installed normally?
- Go to Step 3 Repair axle
parts.
Go to Step 7
3 Is there play in each or any wheel speed sensor?
- Repair wheel
speed sensor.
Go to Step 7 Go to Step 4
4 Is there damage, or powered iron sticking to each or any wheel speed sensor/sensor rotor?
- Replace
wheel speed sensor or
sensor rotor.
Go to Step 7 Go to Step 5
5 Is the speed sensor of each wheel output normal?
- Go to Step 6 Replace
wheel speed sensor or repair
harness.
Go to Step 7
6 Is the 4W D control system function normal?
- 2-4W D Repair
or Go to Step 7 Repair or
replace 2-
4W D control System.
Go to Step 7
7 Reconnect all components, ensure all components are properly mounted.
Is this step finished? - Repeat the
“Basic
diagnostic
flow chart” Go to Step 7



BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

BRAKE CONTROL SYSTEM 5A-43
Uneven Braking Occurs While ABS Works

Step Action Value(s) Yes No
1 Is there play in each or any sensor?
- Repair.
Go to Step 5 Go to Step 2
2 Damage or powdered iron sticking to each or any
sensor/sensor rotor? - Repair.
Go to Step 5 Go to Step 3
3 Is the output normal for each sensor?
- Go to Step 4 Replace
sensor or repair
harness.
Go to Step 5
4 Is brake pipe connecting order correct? Note: Check the EHCU type for specification, when
the EHCU is replaced.
(Specification; 2W D Model or 4W D Model) - Replace
EHCU.
Go to Step 5 Reconnect
brake pipe correctly.
Go to Step 5
5 Reconnect all components, ensure all components are properly mounted.
Is this step finished? - Repeat the
“Basic
diagnostic
flow chart” Go to Step 5

The Wheels Are Locked

Step Action Value(s) Yes No
1 Is ABS working?
- Go to Step 2 Go to Step 4
2 Is vehicle speed under 5 km/h? - Go to Step 3 Normal.
3 Is the output for each normal?
- Go to Step 4 Replace
sensor or repair
harness.
Go to Step 6
4 Is 2-4W D system function normal?
- Go to Step 5 Replace 2-
4W D control
unit or repair harness.
Go to Step 6
5 Is EHCU grounded properly? Note: Check the EHCU type for specification, when
the EHCU is replaced.
(Specification; 2W D Model or 4W D Model) - Replace
EHCU.
Go to Step 6 Repair.
Go to Step 6
6 Reconnect all components, ensure all components are properly mounted.
Is this step finished? - Repeat the
“Basic
diagnostic
flow chart” Go to Step 6


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

5A-44 BRAKE CONTROL SYSTEM
Brake Pedal Feed Is Abnormal

Step Action Value(s) Yes No
1 Is the stop light actuated when the brake pedal is
depressed? - Go to Step 2 Go to Step 3
2 1. Turn the ignition switch off.
2. Disconnect EHCU connector. Is the check voltage for EHCU connector terminals
when brake pedal is depressed than battery voltage? - Go to Step 4 Harness NG
between stop light SW and EHCU.
Go to Step 6
3 Is stop light fuse normal?
- Go to Step 5 Replace stop
light fuse.
Go to Step 6
4 Is the check continuity between EHCU connector to body grounded?
- Go to Step 6 Repair body
grounded harness.
Go to Step 6
5 Is stop light switch operation normal?
- Repair stop
light harness.
Go to Step 6 Replace stop
light switch.
Go to Step 6
6 Reconnect all components, ensure all components are properly mounted.
Is this step finished? - Repeat the
“Basic
diagnostic
flow chart” Go to Step 6


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

BRAKE CONTROL SYSTEM 5A-45
Braking Sound (From EHCU) Is Heard While Not Braking

Step Action Value(s) Yes No
1 Is this the first vehicle start after engine start?
- It is self
checking sound
Normal. Go to Step 2
2 Is vehicle speed at 15 km/h or 30 km/h?
- It is self
checking sound
Normal. Go to Step 3
3 Check for the following condition: • At the time of shift down or clutch operation.
• At the time of low road friction drive (ice or snow on road) or rough road drive.
• At the time of high-speed turn.
• At the time of passing curb.
• At the time of operating electrical equipment switches.
• At the time of racing the engine. Did it occur under any of the conditions above? - ABS may
sometimes be
actuated even when brake pedal is not applied. Go to Step 4
4 Is there play in each or any sensor/wheel speed sensor rotor? - Repair.
Go to Step 7 Go to Step 5
5 Damage or powdered iron sticking to each or any sensor/wheel speed sensor rotor? - Repair.
Go to Step 7 Go to Step 6
6 Is each sensor normal? Note: Check the EHCU type for specification, the
EHCU is replaced.
(Specification; 2W D or 4W D Model)

- Check
harness/
connector for suspected
disconnection
If no
disconnection is found,
replace EHCU
Go to Step 7 Repair.
Go to Step 7
7 Reconnect all components, ensure all components are properly mounted.
Is this step finished? - Repeat the
“Basic
diagnostic
flow chart” Go to Step 7


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

5A-48 BRAKE CONTROL SYSTEM
DTC C0221 (Flash Code 21) Front Right Wheel Speed Sensor Short Circuit or
Circuit Open



RTW 75AMF001301

Step Action Value(s) Yes No
1 W ere the steps of the “Basic Diagnostic Flow Chart”
performed?
- Go to Step 2 Go to Basic
Diagnostic
Flow Chart
2 1. Check for a poor connection at the front right wheel speed sensor harness connector.
2. Check installation condition for front right wheel speed sensor.
3. If a problem is found, repair as necessary. W as a problem found? - Verify repair Go to Step 3
3 1. Ignition “OFF”, disconnect the EHCU and front right
wheel speed sensor.
2. Check the circuit between EHCU and front right wheel speed sensor. (Circuit for an open, short to
ground, or short to voltage.)
3. If a problem is found, repair as necessary. W as a problem found? - Verify repair Go to Step 4

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

5A-52 BRAKE CONTROL SYSTEM
DTC C0225 (Flash Code 25) Front Left Wheel Speed Sensor Short Circuit or
Circuit Open



RTW 75AMF001301

Step Action Value(s) Yes No
1 W ere the steps of the “Basic Diagnostic Flow Chart”
performed?
- Go to Step 2 Go to Basic
Diagnostic
Flow Chart
2 1. Check for a poor connection at the front left wheel speed sensor harness connector.
2. Check installation condition for front left wheel speed sensor.
3. If a problem is found, repair as necessary. W as a problem found? - Verify repair Go to Step 3
3 1. Ignition “OFF”, disconnect the EHCU and front left
wheel speed sensor.
2. Check the circuit between EHCU and front left wheel speed sensor. (Circuit for an open, short to
ground, or short to voltage.)
3. If a problem is found, repair as necessary. W as a problem found? - Verify repair Go to Step 4

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007