Isuzu N-Series. Manual - part 279

5A4-90 ABS/ASR

RR Wheel Speed Sensor Output Check Procedure
Check flow C-1-4

Step

Action

Value

YES

NO

1

1. Turn the starter switch OFF.
2. Disconnect the connector of the EHCU.
3. Jack-up the vehicle to lift the front wheels

off the floor.

4. Connect a 120

Ω resistance between the

J-177 connector terminal 12 and the
ground.

5. Apply a 9 — 16V voltage to the J-177

connector terminal 21.

6. Measure the DC voltage between the J-

177 connector terminal 1 and the ground
while turning the RR wheel half turn/sec.

Is the value within specified value?

0.2 — 4.5V

Go to Step5

Go to Step2

2

1. Turn the starter switch OFF.
2. Disconnect the RR wheel speed sensor

connector J-148.

3. Connect a 120

Ω resistance between the

J-148 connector terminal 2 and the
ground.

4. Apply a 9 — 16V voltage to the J-148

connector terminal 1 (sensor side).

5. Measure the DC voltage between the J-

148 connector terminal 2 and the ground
while turning the RR wheel half turn/sec.

Is the value within specified value?

0.2 — 4.5V

Go to Step3

Go to Step4

3

Repair the circuit for open/short circuit, and
the connector for improper connection
between the connector of EHCU and the sen-
sor connector.

Is this step completed?

—

Go to Step5

—

4

Replace the RR wheel speed sensor.

Is this step completed?

—

Go to Step5

—

5

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 Step5

ABS/ASR 5A4-91

Legend

1. Battery (12V)
2. Tester
3. Resistance
4. Speed sensor

N5A2070E

5A4-92 ABS/ASR

Speed Sensor Output Check Procedure
Check flow TC-1

Used for checking the front speed sensor, or the rear
speed sensor when no DTC is set.

CAUTION:

On the vehicle that the rear tires have smaller diameter,
the rear wheel speed may be indicated a little higher
than the front wheel speed. Check the speed after driv-
ing a while at a constant speed.

Step

Action

Value

YES

NO

1

1. Connect the Tech 2.
2. Check each sensor lowest speed from

the “Wheel sensor”.

Is the sensor speed 4km/h (2 mph) or more?

—

Go to Step2

Go to Step6

2

Check the suspicious sensor circuit for open
circuit. (Check with shaking the wire and the
connector.)

Is the sensor circuit connection normal?

—

Replace the 

speed sensor.Go 

to Step3

Repair.Go to 

Step2

3

Check each sensor lowest speed from the
“Wheel sensor”.

Is the sensor speed 4km/h (2 mph) or more?

—

Go to Step4

Go to Step6

4

Check the sensor rotor.

Is the sensor rotor normal?

—

Go to Step5

Replace the sen-

sor rotor. Go to 

Step5

5

Check each sensor lowest speed from the
“Wheel sensor”.

Is the sensor speed 4km/h (2 mph) or more?

—

Repair the circuit 

or connector 

between the 

EHCU and the 

speed sensor. Go 

to Step6

Go to Step6

6

Install all the components, and check that
those are installed properly.

Is this step completed?

—

Repeat “Diagnos-

tic basic flow”.

Go to Step6

ABS/ASR 5A4-93

Rear Sensor Rotor

Components

Legend

1. Axle shaft, outer oil seal
2. Bearing lock washer, lock nut
3. Outer bearing, bearing lock nut
4. Hub and drum
5. Sensor rotor

6. Inner bearing
7. Inner oil seal
8. Rear speed sensor
9. Harness connector

Removal

• Refer to the rear speed sensor removal proce-

dure.

1. Rear sensor rotor

• Use a puller to take out the sensor rotor.

2. Inner oil seal

• Remove the inner oil seal.

3. Inner bearing

• Remove the inner bearing.
• Rotor runout must be 

±0.1 mm (0.004 in) or less

with the rotor installed.

N5A2057E

N5A2071E