Isuzu N-Series. Manual - part 270

5A4-54 ABS/ASR

DTC:C0254 (Flash Code 54) Speed Sensor Open/Short Circuit; RR

Check flow B-16

Step

Action

Value

YES

NO

1

1. Turn the starter switch OFF.
2. Disconnect the connector of EHCU and

the RR wheel speed sensor connector J-
148.

3. Check for continuity between the J-177

connector terminal 12 and the J-148 sen-
sor connector terminal 2.

Is there continuity?

—

Go to Step2

Go to Step7

2

Check for continuity between the J-177 con-
nector terminals 12 and 1.

Is there continuity?

—

Go to Step7

Go to Step3

3

Check for continuity between the J-177 con-
nector terminal 21 and the J-148 sensor con-
nector terminal 1.

Is there continuity?

—

Go to Step4

Go to Step7

4

Check for continuity between the J-177 con-
nector terminals 21 and 1.

Is there continuity?

—

Go to Step7

Go to Step5

5

1. Connect the connector of the EHCU.
2. Turn the starter switch ON.
3. Measure the voltage between the J-148

sensor connector terminal 1 and the
ground.

Is the value within specified value?

9 — 16V

Go to Step6

Go to Step7

6

Check the RR wheel speed sensor output.
(Refer to the check flow C-1-4.)

Is the fail corrected?

—

Go to Step8

Go to Step8

7

Repair the circuit for open/short circuit, and
the connector for improper connection
between the connector of EHCU and the
speed sensor connector.

Is this step completed?

—

Go to Step9

Go to Step7

8

Replace the control unit.

Is this step completed?

—

Go to Step9

Go to Step8

9

1. Install all the components, and check that

those are installed properly.

2. Clear the DTC.

Is this step completed?

—

Go to “Diagnostic 

basic flow”.

Go to Step9

ABS/ASR 5A4-55

DTC:C0261 (Flash Code 61) Speed Sensor Signal Fault/Wrong Tire Size; FL

Check flow B-17

Step

Action

Value

YES

NO

1

Check the tire.

Is the tire specification correct? Is abnormal
wear found in the outer surface?

—

Go to Step2

Replace with the 

specified tire with-

out wear.Go to 

Step21

2

Has certain tire been rotated alone by perfum-
ing for jack-up or roller tester?

—

DTC may be set if 

certain tire is 

rotated alone. Go 

to Step21

Go to Step3

3

Is the FL wheel bearing rattling?

—

Go to Step12

Go to Step4

4

Is the FL wheel speed sensor/sensor rotor rat-
tling?

—

Go to Step13

Go to Step5

5

Is iron powder attached to the FL wheel speed
sensor/sensor rotor?

—

Go to Step14

Go to Step6

6

Check the FL wheel speed sensor. (Refer to
the check flow C-1-1 or TC-1.)

Is the FL sensor output normal?

—

Go to Step7

Go to Step10

7

Does the sensor rotor have missing tooth or
saw-toothed?

—

Go to Step15

Go to Step8

8

Measure the resistance between the B-177
connector terminals 33 and the ground.

Is the value within specified value?

1000k

Ω or 

more

Go to Step9

Go to Step11

9

1. Clear the DTC.
2. Test run the vehicle, and perform the self-

diagnosis.

Is DTC displayed repeatedly?

—

Go to Step20

Go to Step18

10

Is the speed sensor damaged or saw-
toothed?

—

Go to Step16

Go to Step17

11

1. Disconnect the FL sensor connector.
2. Measure the resistance between the J-75

connector terminal 2 (sensor side) and
the ground.

Is the value within specified value?

1000k

Ω or 

more

Go to Step19

Go to Step16

12

Adjust the preload of the wheel bearing.

Is this step completed?

—

Go to Step21

—

13

Repair or replace the speed sensor/sensor
rotor.

Is this step completed?

—

Go to Step21

—

14

Repair the speed sensor/sensor rotor.

Is this step completed?

—

Go to Step21

—

15

Replace the sensor rotor.

Is this step completed?

—

Go to Step21

—

16

Replace the FL wheel speed sensor.

Is this step completed?

—

Go to Step21

—

5A4-56 ABS/ASR

17

Check the FL wheel speed sensor circuit.
(Refer to the check flow B-13.)

Is this step completed?

—

Check the repair.

—

18

Check the circuit for open circuit, and the con-
nector for improper connection between the
EHCU and the speed sensor connector. Refer
to “Intermittent trouble”.

Is this step completed?

—

Go to Step21

—

19

Repair the circuit for open/short circuit, and
the connector for improper connection
between the EHCU connector and the speed
sensor connector.

Is this step completed?

—

Go to Step21

Go to Step21

20

Replace the EHCU.

Is this step completed?

—

Go to Step21

—

21

1. Install all the components, and check that

those are installed properly.

2. Clear the DTC.

Is this step completed?

—

Go to “Diagnostic 

basic flow”.

Go to Step21

Step

Action

Value

YES

NO

ABS/ASR 5A4-57

DTC:C0262 (Flash Code 62) Speed Sensor Signal Fault/Wrong Tire Size; FR

Check flow B-18

Step

Action

Value

YES

NO

1

Check the tire.

Is the tire specification correct? Is abnormal
wear found in the outer surface?

—

Go to Step2

Replace with the 

specified tire with-

out wear.Go to 

Step21

2

Has certain tire been rotated alone by perfum-
ing for jack-up or roller tester?

—

DTC may be set if 

certain tire is 

rotated alone. Go 

to Step21

Go to Step3

3

Is the FR wheel bearing rattling?

—

Go to Step12

Go to Step4

4

Is the FR wheel speed sensor/sensor rotor
rattling?

—

Go to Step13

Go to Step5

5

Is iron powder attached to the FR wheel
speed sensor/sensor rotor?

—

Go to Step14

Go to Step6

6

Check the FR wheel speed sensor. (Refer to
the check flow C-1-2 or TC-1.)

Is the FR sensor output normal?

—

Go to Step7

Go to Step10

7

Does the sensor rotor have missing tooth or
saw-toothed?

—

Go to Step15

Go to Step8

8

Measure the resistance between the B-177
connector terminal 11 and the ground.

Is the value within specified value?

1000k

Ω or 

more

Go to Step9

Go to Step11

9

1. Clear the DTC.
2. Test run the vehicle, and perform the self-

diagnosis.

Is DTC displayed repeatedly?

—

Go to Step20

Go to Step18

10

Is the speed sensor damaged or saw-
toothed?

—

Go to Step16

Go to Step17

11

1. Disconnect the FR sensor connector.
2. Measure the resistance between the J-74

connector terminal 2 (sensor side) and
the ground.

Is the value within specified value?

1000k

Ω or 

more

Go to Step19

Go to Step16

12

Adjust the preload of the wheel bearing.

Is this step completed?

—

Go to Step21

—

13

Repair or replace the speed sensor/sensor
rotor.

Is this step completed?

—

Go to Step21

—

14

Repair the speed sensor/sensor rotor.

Is this step completed?

—

Go to Step21

—

15

Replace the sensor rotor.

Is this step completed?

—

Go to Step21

—

16

Replace the FR wheel speed sensor.

Is this step completed?

—

Go to Step21

—