2007 ISUZU KB P190 ignition

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.


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ISUZU KB P190 2007

5A-34 BRAKE CONTROL SYSTEM
Warning Lamp System Control Main Items DTC
(Flash Code) Description
ABS Brake
(EBD) ABS EBD


× × Battery, W iring or EHCU
(less than 8V) C0277 (77) System Voltage Low

× × Battery or W iring
(less than 10V)
C0278 (78) System Voltage High
× × Battery or W iring EHCU
C0282
(82) 4 W heel Drive State Input Signal
Failure × × W iring
C0285
(85) Control Module Vehicle Options
Incorrect × × Vehicle (Sensor or EHCU)

*A : W hen three or more failures are detected, the EBD warning lamp is "ON" and control is canceled.
*B : The ABS lamp is “OFF” when the ABS lamp is “ON” after a repair, until the vehicle’s speed becomes
more than 10km/h (6mph) in the following ignition
cycle and failure is not detected.


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ISUZU KB P190 2007

5A-38 BRAKE CONTROL SYSTEM
Basic Diagnostic Flow Chart



RTW 75ALF000201
Step Action Value(s) Yes No
1 1. Ignition “ON”, engine “OFF”.
2. Observe the ABS warning lamp. Note: If the starter switch is turned ON, the ABS
warning lamp will turn on and then turn off after 3
seconds.
Is the ABS warning lamp “ON”? - Go to Step 2 Go to “No
ABS warning lamp”
2 1. Ignition “OFF”.
2. Install Tech 2.
3. Ignition “ON”.
4. Attempt to display ABS data with the Tech 2. Does the Tech 2 display ABS data? - Go to Step 5 Go to Step 3

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ISUZU KB P190 2007

BRAKE CONTROL SYSTEM 5A-39
Step Action Value(s) Yes No
3 1. Ignition “OFF”, disconnect the EHCU.
2. Check the DLC (Data Link Connector) circuit for an open, short to ground, or short to voltage.
Also, check the DLC ignition feed circuit for an open
or short to ground and the DLC ground circuit for an
open.
3. If a problem is found, repair as necessary. W as a problem found? - Go to Step 2 Go to Step 4
4 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? - Go to Step 2 Go to Step 11
5 Select “Display DTCs” with the Tech 2.
Are any DTCs stored? - Go to Step 6 Go to Step 10
6 Review and record for Tech 2 Failure Records data
and DTCs.
Is the action complete? - Go to Step 7 -
7 The DTC is then stored. Is this DTC C0271 stored?
- Go to
applicable
DTC table
after Go to step 8 Go to Step 8
8 Clear the DTCs by “Clear the Information“ with Tech 2.
Did the DTCs clear? - Go to Step 9 -
9 Select “Display DTCs” with the Tech 2. Are any DTCs stored? - Go to
applicable
DTC table Go to Step 10
10 Review and record for Tech 2 data.
Is the action complete?
- Go to
Symptom
Diagnosis and Go to Basic Inspection
Procedure -
11 Replace the 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

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%)


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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


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ISUZU KB P190 2007

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

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