Isuzu KB P190. Manual — part 168

BRAKE CONTROL SYSTEM 5A-79

Step Action Value(s) Yes

No

6

1. Remove the G sensor.

2. Reconnect G sensor and EHCU

3. Install the Tech 2.

4. Ignition "ON", engine "OFF".

5. Observe the G sensor reading on Tech 2.

If G sensor inclines, reading voltage will change.

Is the reading voltage between specified values?

1.0 - 4.0V

Go to Step 7

Go to Step 8

7

1. Ignition "OFF".

2. Install the G sensor.

3. Install the Tech 2.

4. Ignition "ON", engine "OFF".

5. Select "Display DTCs" with the Tech 2.

Are any DTCs stored?

-

Go to Step 8

Verify repair

8

1. Replace G 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
Tech 2.

Are any DTCs stored?

-

Go to Step 9

Verify repair

9 Replace

EHCU.

Note: Check the EHCU type for specification, when
the EHCU is replaced.

(Specification ; 2WD model or 4WD model)

Is the action complete?

-

Verify repair

-

5A-80 BRAKE CONTROL SYSTEM

DTC C0277 (Flash Code 77) System Voltage Low
DTC C0278 (Flash Code 78) System Voltage High

RTW75ALF000301

Step Action Value(s) Yes

No

1

Were 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 EHCU

2. If a problem is found, repair as necessary.

Was a problem found?

-

Verify repair

Go to Step 3

3

1. Ignition “OFF”, disconnect EHCU.

2. Ignition “ON”, engine “OFF”.

3. Check the supply voltage to EHCU.

Is the value normal?

Battery

Voltage

Go to Step 5

Go to Step 4

4

Repair or replace the power supply circuit.

Is the action complete?

-

Verify repair

-

BRAKE CONTROL SYSTEM 5A-81

Step Action Value(s) Yes

No

5

1. Check the power supply circuit.

(Check circuit for an open, short to ground, or short
to voltage.)

2. If a problem is found, repair as necessary.

Was a problem found?

-

Verify repair

Go to Step 6

6

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 7

Verify repair

7 Replace

EHCU.

Note: Check the EHCU type for specification, when
the EHCU is replaced.

(Specification ; 2WD model or 4WD model)

Is the action complete?

-

Verify repair

-

5A-82 BRAKE CONTROL SYSTEM

DTC C0282 (Flash Code 82) 4 Wheel Drive State Input Signal Failure

RTW75AMF001501

Step Action Value(s) Yes

No

1

Were 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 EHCU and 2-4WD

control unit.

2. 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 2-4WD

control unit.

2. Check the circuit between EHCU and 2-4WD

control unit. (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

4

1. Check the 2-4WD Control system.

2. If a problem is found, repair as necessary.

Was a problem found?

-

Verify repair

Go to Step 5