Fig Identifying ABS Warning Light And Vsc Trac Warning Light Blink Reference Chart

ABS warning light circuit

ABS WARNING LIGHT REMAINS ON or ABS WARNING LIGHT DOES NOT COME ON

VSC TRAC warning light circuit

VSC TRAC WARNING LIGHT REMAINS ON or VSC TRAC

WARNING LIGHT DOES NOT COME ON

TS terminal circuit

TS AND CG TERMINAL CIRCUIT

b. Check the yaw rate and deceleration sensor.

Shift the shift lever to the D position and drive the vehicle at a vehicle speed of approx. 3 mph (5 km/h), turn the steering wheel either to the left or right for 90° or more, and turn the vehicle through 180 degrees. Check that the VSC buzzer sounds for 3 seconds upon start off.

Stop the vehicle and shift the shift lever to the P position, check that the VSC buzzer sounds again

2007 BRAKES Brake Control - Sequoia for 3 seconds.

Stsri Position ■

End Position

O C1S39taC51

Fig. 12: Checking Yaw Rate And Deceleration Sensor

HINT:

• If the VSC buzzer sounds twice, the sensor check has been completed normally.

• If the VSC buzzer does not sound, check the VSC buzzer circuit (see VSC BUZZER CIRCUIT ), then do the sensor check again.

• Drive the vehicle through 180°. At the end of the turn its check, the direction of the vehicle should be within 180° +- 51° of its start position.

• If the buzzer sounds after start off, then the deceleration sensor check has passed its check. If the buzzer sounds at the completion of a turn its check, then the yaw rate sensor check has passed. The buzzer sound should be heard during the sensor checks.

c. Check the master cylinder pressure sensor.

1. Turn the ignition switch to the ON position.

2. Keep the vehicle in a stationary condition on a level surface for 2 sec. or more.

3. Keeping the vehicle in a stationary condition and not pressing on the brake pedal for 1 sec. or more, depress the brake pedal with 147 N (15 kgf, 33 lbf) or more for 2 sec. or more on a new ECU.

NOTE: If zero point calibration has never been performed on a new ECU, master cylinder pressure sensor check cannot be completed correctly. Perform zero point calibration first (See CALIBRATION ).

HINT:

At this time, the buzzer sounds for 3 seconds.

d. Check the speed sensor.

Drive the vehicle straight forward

2007 BRAKES Brake Control - Sequoia

When driving the vehicle at the speed of 28 mph (45 km/h) or higher for several seconds, check that the ABS warning light goes off.

HINT:

There is a case that the sensor check is not completed if the vehicle has its wheels spun or its steering wheel turned during this check.

e. Stop the vehicle.

f. Read the DTC by following the prompts on the tester screen. HINT:

Refer to the for further details. 3. DTC of ABS sensor check function:

DTC CHA]

RT

Code No.

Diagnosis

Trouble Area

C1271/71

Low output voltage of right front speed sensor

• Right front speed sensor

• Sensor installation

• Sensor rotor

C1272/72

Low output voltage of left front speed sensor

• Left front speed sensor

• Sensor installation

• Sensor rotor

C1273/73

Low output voltage of right rear speed sensor

• Right rear speed sensor

• Sensor installation

• Sensor rotor

C1274/74

Low output voltage of left rear speed sensor

• Left rear speed sensor

• Sensor installation

• Sensor rotor

C1275 / 75

Abnormal change in output voltage of right front speed sensor

Right front speed sensor rotor

C1276/76

Abnormal change in output voltage of left front speed sensor

Left front speed sensor rotor

C1277/77

Abnormal change in output voltage of right rear speed sensor

Right rear speed sensor rotor

C1278/78

Abnormal change in output voltage of left rear speed sensor

Left rear speed sensor rotor

C1279/79

Deceleration sensor is faulty

• Deceleration sensor

• Sensor installation

C1281/81

Master cylinder pressure sensor output signal is faulty

Master cylinder pressure sensor

2007 BRAKES Brake Control - Sequoia

HINT:

Read the number of blinks of the ABS warning light. DTC of VSC sensor check function

DTC CHA]

RT

Code No.

Diagnosis

Trouble Area

C0371 /71

Yaw rate sensor output signal malfunction

• Yaw rate sensor circuit

HINT:

HINT:

Read the number of blinks of the VSC TRAC warning light. PROBLEM SYMPTOMS TABLE

If a normal code is indicated during the DTC check but the problem still occurs, check the circuits for each problem symptom in the order given in the table below and proceed to the relevant troubleshooting page.

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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