2004 ISUZU TF SERIES sensor

5A-42 BRAKE CONTROL SYSTEM

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 under 10 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
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 one condition 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; 2WD or 4WD 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.
Was this step finished?
- Repeat the
“Basic
diagnostic
flow chart” Go to Step 7

5A-44 BRAKE CONTROL SYSTEM

DTC C0221 (Flash Code 21) Front Right Wheel Speed Sensor Short Circuit or
Circuit Open

LTW35AMF000101

Step Action
Value(s) Yes No
1 Was 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.
Was 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.
Was a problem found?
- Verify repair Go to Step 4

BRAKE CONTROL SYSTEM 5A-45

Step Action
Value(s) Yes No
4 1. Replace front right wheel speed sensor.
2. Select “Display DTCs” with the Tech 2.
Note : Perform the various tests (actuator test, test
run, brake test, etc.) then observe the DTC with a
Tech2.
Are any DTCs stored? - Go to Step 5 Verify repair
5 Replace EHCU.
Note : Check the EHCU type for specification, when
the EHCU is replaced.
(Specification ; 2WD model or 4WD model)
Was the action complete? - Verify repair -

5A-46 BRAKE CONTROL SYSTEM

DTC C0222 (Flash Code 22) Front Right Wheel Speed Sensor Incorrect Signal

LTW35AMF000101

Step Action Value(s) Yes No
1 Was 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.
Was 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. (short to ground, or short to
voltage.)
3. If a problem is found, repair as necessary.
Was a problem found?
- Verify repair Go to Step 4
4 1. Replace front right wheel speed sensor.
2. Select “Display DTCs” with the Tech 2.
Note : Perform the various tests (actuator test, test
run, brake test, etc.) then observe the DTC with a
Tech2.
Are any DTCs stored? - Go to Step 5 Verify repair

BRAKE CONTROL SYSTEM 5A-47

Step Action Value(s) Yes No
5 Repair or replace the front right sensor rotor at front
hub.
Was the action complete? - Verify repair
Go to Step 6 -
6 Select “Display DTCs” with the Tech 2.
Note : Perform the various tests (actuator test, test
run, brake test, etc.) then observe the DTC with a
Tech2.
Are any DTCs stored? - Go to Step 7 Verify repair
7 Replace EHCU.
Note : Check the EHCU type for specification, when
the EHCU is replaced.
(Specification ; 2WD model or 4WD model)
Was the action complete? - Verify repair -

5A-48 BRAKE CONTROL SYSTEM

DTC C0223 (Flash Code 23) Front Right Wheel Speed Sensor Signal - Tooth
Chipping

LTW35AMF000101

Step Action
Value(s) Yes No
1 Was 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.
Was a problem found?
- Verify repair Go to Step 3
3 1. Check condition for sensor rotor at front hub.
2. If a problem is found, repair as necessary.
Was a problem found?
- Verify repair Go to Step 4
4 1. Ignition “OFF,” disconnect the EHCU and front right
wheel speed sensor.
2. Check the circuit between EHCU and front right
wheel speed sensor. (short to ground, or short to
voltage.)
3. If a problem is found, repair as necessary.
Was a problem found?
- Verify repair Go to Step 5

BRAKE CONTROL SYSTEM 5A-49

Step Action
Value(s) Yes No
5 1. Replace front right wheel speed sensor.
2. Select “Display DTCs” with the Tech 2.
Note : Perform the various tests (actuator test, test
run, brake test, etc.) then observe the DTC with a
Tech2.
Are any DTCs stored? - Go to Step 6 Verify repair
6 Replace EHCU.
Note : Check the EHCU type for specification, when
the EHCU is replaced.
(Specification ; 2WD model or 4WD model)
Was the action complete? - Verify repair -

5A-50 BRAKE CONTROL SYSTEM

DTC C0225 (Flash Code 25) Front Left Wheel Speed Sensor Short Circuit or
Circuit Open

LTW35AMF000101

Step Action
Value(s) Yes No
1 Was 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.
Was 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.
Was a problem found?
- Verify repair Go to Step 4