Toyota Sequoia (2005). Manual - part 283

–

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

DI–927

1121

INSPECTION PROCEDURE

HINT:
Start the inspection from step 1 when using the hand–held tester and start from step 2 when not using the
hand–held tester.

1

Check output value of speed sensor.

PREPARATION:
(a)

Connect the hand–held tester to the DLC3.

(b)

Turn the ignition switch to the ON position and push the hand–held tester main switch ON.

(c)

Select DATA LIST mode on the hand–held tester.

CHECK:
Check that there is no difference between the speed value output from the speed sensor displayed by the
hand–held tester and the speed value displayed by the speedometer when driving the vehicle.

Item

Measurement Item /

Range (Display)

Normal Condition

Diagnostic Note

WHEEL SPD FR

Wheel speed sensor (FR)
reading / min.: 0 MPH (0
km/h), max.: 202 MPH
(326 km/h)

Actual wheel speed

Similar speed as indicated
on speedometer

WHEEL SPD FL

Wheel speed sensor (FR)
reading / min.: 0 MPH (0
km/h), max.: 202 MPH
(326 km/h)

Actual wheel speed

Similar speed as indicated
on speedometer

WHEEL SPD RR

Wheel speed sensor (FR)
reading / min.: 0 MPH (0
km/h), max.: 202 MPH
(326 km/h)

Actual wheel speed

Similar speed as indicated
on speedometer

WHEEL SPD RL

Wheel speed sensor (FR)
reading / min.: 0 MPH (0
km/h), max.: 202 MPH
(326 km/h)

Actual wheel speed

Similar speed as indicated
on speedometer

OK:

There is almost no difference from the displayed speed value.

HINT:
There is tolerance of 

±

 10 % in the speedometer indication.

OK

Go to step 4.

NG

R14205

2

1

R14205

2

1

DI–928

–

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

1122

2

Check speed sensor.

Front:
PREPARATION:
(a)

Make sure that there is no looseness at the connector
lock part and connecting part of the connector.

(b)

Disconnect the speed sensor connector.

CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector.
OK:

Resistance: 0.92 

to 1.22 

k

Ω

CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector and body ground.
OK:

Resistance: 1 M

Ω

 or higher

Rear:
PREPARATION:
(a)

Make sure that there is no looseness at the connector
lock part and connecting part of the connector.

(b)

Disconnect the speed sensor connector.

CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector.
OK:

Resistance: 1.8 to 2.2 k

Ω

CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector and body ground.
OK:

Resistance: 1 M

Ω

 or higher

NG

Replace speed sensor 
(See page 

BR–56

 or 

BR–59

).

NOTICE:
Check the speed sensor signal after replacement (See
page 

DI–899

).

OK

BR3795

OK

NG

–

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

DI–929

1123

3

Check for open and short circuit in harness and connector between each speed
sensor and skid control ECU (See page 

IN–35

).

NG

Repair or replace harness or connector.

OK

4

Check sensor installation.

CHECK:
Check the speed sensor installation.
OK:

The installation bolt is tightened properly and there is
no clearance between the sensor and the front steer-
ing knuckle or the rear axle carrier.
Torque: 8.0 N·m (82 kgf·cm, 71 in.·lbf)

NG

Replace speed sensor 
(See page 

BR–56

 or 

BR–59

).

NOTICE:
Check the speed sensor signal after replacement (See
page 

DI–899

).

OK

W04200

Normal Signal Waveform

1 V / Division

2 m/s / Division

GND

R07880

DI–930

–

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

1124

5

Check speed sensor and sensor rotor serrations.

INSPECTION USING OSCILLOSCOPE
PREPARATION:
Connect the oscilloscope to the terminal FR+ – FR–, FL+ – FL–,
RR+ – RR– and RL+ – RL– of the skid control ECU.
CHECK:
Drive the vehicle at about 12 mph (20 km/h), and check the sig-
nal waveform.
OK:

A waveform as shown in the figure should be output.

HINT:

As the vehicle speed (wheel revolution speed) increases,
a cycle of the waveform becomes shorter and the fluctua-
tion in the output voltage becomes greater.

When noise is identified in the waveform on the oscillo-
scope, error signals are generated due to the speed sen-
sor rotor’s scratches, looseness or foreign matter depos-
ited on it.

OK

Replace skid control ECU
(See page 

BR–52

).

NOTICE:
When replacing the skid control ECU, perform the zero
point calibration (See page 

DI–897

).

NG

6

Check sensor rotor and sensor tip.

Front:
PREPARATION:
Remove the disc (See page 

SA–22

).

CHECK:
Check the sensor rotor serrations.
OK:

No scratches, missing teeth or foreign objects.

PREPARATION:
Remove the front speed sensor (See page 

BR–56

).

CHECK:
Check the sensor tip.
OK:

No scratches or foreign objects on the sensor tip.

HINT:
Remove any foreign matter if identified. 
Check the output waveform again after reassembly.