Page 638 of 6020

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
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ISUZU KB P190 2007
Page 639 of 6020

5A-46 BRAKE CONTROL SYSTEM
No ABS Warning Lamp
Step Action Value(s) Yes No
1 Check the meter fuse for the instrument cluster
ignition feed circuit.
Is the fuse OK? - Go to Step 3 Go to Step 2
2 Replace the fuse. Is the action complete? - Verify repair
Go to Step 3 -
3 1. Ignition “OFF”, disconnect the EHCU. 2. Ignition “ON”, engine “OFF”.
3. Observe the ABS warning lamp. Is the ABS warning lamp “ON”? - Go to Step 5 Go to Step 4
4 Repair or replace the meter circuit or meter.
Is the action complete? - Verify repair -
5 1. Check the EHCU circuit for an open, short to
ground, or short to voltage. Also, check the EHCU
ignition feed circuit for an open or short to ground
and the EHCU ground circuit for an open.
2. If a problem is found, repair as necessary. W as a problem found? - Verify repair Go to Step 6
6 1. Ignition “OFF”, reconnect the EHCU.
2. Ignition “ON”,engine “OFF”.
3. Observe the ABS warning lamp. Is the ABS warning lamp “ON”? - Verify repair Go to Step 7
7 Replace EHCU.
Note: Check the EHCU type for specification, the
EHCU is replaced.
(Specification; 2W D or 4W D Model)
Is the action complete? - Verify repair -
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ISUZU KB P190 2007
Page 640 of 6020
BRAKE CONTROL SYSTEM 5A-47
ABS Warning Lamp ON Steady
Step Action Value(s) Yes No
1 1. Check the ABS warning lamp lighting circuit for a
short.
2. If a problem found, repair as necessary. W as a problem found? - Go to Step 3 Go to Step 2
2 1. Check the ABS warning lamp lighting circuit at the
meter for a short. Refer to METER, W ARNING
LIGHT AND INDICATOR LIGHT in 8 section.
2. If a problem is found, repair or replace the meter. W as a problem found? - Go to Step 3 Go to Step 4
3 1. Connect all connectors.
2. Ignition “ON”, engine “OFF”.
3. W ait for about 10 seconds.
4. Observe the ABS warning lamp. Is the ABS warning lamp turned “OFF”? - Verify repair Go to Step 4
4 Replace EHCU.
Note: Check the EHCU type for specification, the
EHCU is replaced.
(Specification; 2W D or 4W D Model)
Is the action complete? - Verify repair -
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ISUZU KB P190 2007
Page 657 of 6020

5A-64 BRAKE CONTROL SYSTEM
DTC C0238 (Flash Code 38) Front Speed Sensor Correlation
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 the tire size of each wheels.
2. If the tire size is different, replace the tire.
3. If a problem is found, repair as necessary. W as a problem found? - Verify repair Go to Step 3
3 1. Check for the gear ratio of a front axle differential gear and a rear axle differential gear.
2. If the gear ratio is different, repair the gear ratio.
3. If a problem is found, repair as necessary. W as a problem found? - Verify repair Go to Step 4
4 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
Tech 2.
Are any DTCs stored? - Go to Step 5 Verify repair
5 1. Check for a poor connection at the wheel speed sensor harness connector.
2. Check installation condition for wheel speed sensor.
3. If a problem is found, repair as necessary. W as a problem found? - Verify repair Go to Step 6
6 1. Check condition for sensor rotor.
2. If a problem is found, repair as necessary. W as a problem found? - Verify repair Go to Step 7
7 1. Ignition “OFF” disconnect the EHCU and wheel
speed sensor.
2. Check the circuit between EHCU and wheel speed sensor. (short ground, or short to voltage)
3. If a problem is found, repair as necessary. W as a problem found? - Verify repair Go to Step 8
8 1. Ignition “OFF”.
2. Check the EHCU circuit for an open, short to ground, or short to voltage. Also, check the EHCU
ignition feed circuit for an open or short to ground
and the EHCU ground circuit for an open or short to
voltage.
3. If a problem is found, repair as necessary. W as a problem found? - Verify repair Go to Step 9
9 1. Ignition “ON”, engine “OFF”.
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
Tech 2.
Are any DTCs stored? - Go to Step 10 Verify repair
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ISUZU KB P190 2007
Page 660 of 6020
BRAKE CONTROL SYSTEM 5A-67
Step Action
Value(s) Yes No
3 1. Ignition “ON”, engine “OFF”.
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
Tech 2.
Are any DTCs stored? - Go to Step 4 Verify repair
4 Replace EHCU.
Note: Check the EHCU type for specification, when
the EHCU is replaced.
(Specification ; 2W D model or 4W D model)
Is the action complete? - Verify repair -
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ISUZU KB P190 2007
Page 662 of 6020
BRAKE CONTROL SYSTEM 5A-69
Step Action
Value(s) Yes No
3 1. Ignition “ON”, engine “OFF”.
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
Tech 2.
Are any DTCs stored? - Go to Step 4 Verify repair
4 Replace EHCU.
Note: Check the EHCU type for specification, when
the EHCU is replaced.
(Specification ; 2W D model or 4W D model)
Is the action complete? - Verify repair -
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ISUZU KB P190 2007
Page 664 of 6020
BRAKE CONTROL SYSTEM 5A-71
Step Action
Value(s) Yes No
3 1. Ignition “ON”, engine “OFF”.
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
Tech 2.
Are any DTCs stored? - Go to Step 4 Verify repair
4 Replace EHCU.
Note: Check the EHCU type for specification, when
the EHCU is replaced.
(Specification ; 2W D model or 4W D model)
Is the action complete? - Verify repair -
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ISUZU KB P190 2007
Page 666 of 6020
BRAKE CONTROL SYSTEM 5A-73
Step Action
Value(s) Yes No
3 1. Ignition “ON”, engine “OFF”.
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
Tech 2.
Are any DTCs stored? - Go to Step 4 Verify repair
4 Replace EHCU.
Note: Check the EHCU type for specification, when
the EHCU is replaced.
(Specification ; 2W D model or 4W D model)
Is the action complete? - Verify repair -
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007