2006 TOYOTA RAV4 warning

BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEMBC–15
BC
(1) Operation description:
When the system is in operation, the following
occurs: 1) the slip indicator light blinks; 2) the
VSC light comes on; and 3) when hill-start assist
control operation starts, the skid control buzzer
sounds once; when hill-start assist control
operation ends, the skid control buzzer sounds
twice.
The VSC warning light comes on when the hill-
start assist control is malfunctioning.
(h) AUTO LSD (Auto Limited Slip Differential) for 2WD:
The AUTO LSD achieves the equivalent functions of
an LSD (Limited Slip Differential) through the use of
a traction control system. When the driver presses
the AUTO LSD switch, this system achieves the
LSD effect by regulating the hydraulic pressure that
acts on the drive wheels and controlling the engine
output in accordance with the amount of pedal effort
applied on the accelerator. The AUTO LSD
operates with the AUTO LSD switch on and the
accelerator pedal depressed.
Auto LSD restrains brake pressure and reduces
differential movement, thus transmitting the drive
torque to the other drive wheel to ensure stability
under the following conditions:
• Wheels run off the road.
• Drive wheels spin in place when starting on a
slope with one wheel on snow/ice.
HINT:
Releasing the accelerator pedal cancels control of
the AUTO LSD system.

BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEMBC–17
BC
(1) Operation description:
The skid control ECU determines that the
vehicle is in a state in which the AUTO LSD can
operate by using various sensors and switches
to detect the operating conditions of the AUTO
LSD switch, shift position, accelerator pedal, and
brake pedal. When the vehicle is in a state in
which the AUTO LSD can operate, the skid
control ECU effects hydraulic pressure control of
the wheel cylinder at the wheel with the faster
wheel speed so that the wheel speeds of the
right and left drive wheels will become equal.
The slip indicator light blinks and the AUTO LSD
indicator light comes on when the system is
operating. Both the VSC warning light and SLIP
indicator light come on when the AUTO LSD
system malfunctions.
2. COOPERATIVE CONTROL FUNCTION
(a) Description
(1) Braking when Surface Resistance Differs
Between Left and Right Wheels
If the driver suddenly applies the brakes on a
road surface with a considerable difference in
friction coefficient between the right and left
wheels, the difference in the brake force
between the right and left wheels will cause the
vehicle posture to become unstable and create a
yaw movement. In this state, the skid control
ECU controls the VSC to stabilize the vehicle
posture. At the same time, it effects cooperative
control with the EPS to provide steering torque
assist, which facilitates the driver's steering
maneuvers to stabilize the vehicle posture.
(2) Accelerating when Surface Resistance Differs
Between Left and Right Wheels
If the driver suddenly starts off or accelerates on
a road surface with a considerable difference in
friction coefficient between the right and left
wheels, the slippage of a drive wheel will cause
the vehicle posture to become unstable and
negatively affect its acceleration performance. In
this state, the skid control ECU causes the TRC
to control the hydraulic brake of the slipping
drive wheel, and requests the engine ECU to
effect engine output control. At the same time, it
effects cooperative control with the EPS to
provide steering torque assist, which facilitates
the driver's steering maneuvers to stabilize the
vehicle posture.

BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEMBC–19
BC
4. FAIL SAFE FUNCTION
(a) When a failure occurs in the ABS with BA, TRC and
VSC systems, the ABS and VSC warning lights
illuminate, the slip indicator light comes on*1 or
remains off*2, and the operations of those systems
are prohibited. In addition to this, when a failure
which disables the EBD operation occurs, the brake
warning light comes on and its operation is
prohibited.
HINT:
*1: for 2WD
*2: for 4WD
(b) If control is prohibited due to a malfunction during
operation, control is disabled gradually to avoid
sudden vehicle instability.
5. INITIAL CHECK
(a) When the vehicle speed first reaches approximately
6 km/h (4 mph) or more after the ignition switch is
turned ON, each solenoid valve and the motor of the
ABS and TRACTION actuator are sequentially
activated to perform electrical checks. During the
initial check, the operating sound of the solenoid
valve and motor can be heard from the engine
compartment, but this does not indicate a
malfunction.
6. SERVICE MODE
(a) VSC operation can be disabled by operating the
intelligent tester.
HINT:
Refer to the intelligent tester operator's manual for
further details.
7. FUNCTION OF COMPONENTS
Components Functions
Speed Sensor
(Semiconductor Type)Detects the wheel speed and sends the signal to skid
control ECU
Skid Control ECU
(Housed in ABS and TRACTION Actuator)• Processes the signals from each sensor to control the
ABS, BA, TRC, and VSC
• Sends and receives control signals to and from the
ECM, yaw rate and deceleration sensor, steering
sensor, etc. via CAN communication.
ABS and TRACTION Actuator • Consists of the master cylinder cut solenoid valve,
holding solenoid valve, pressure reduction solenoid
valve, pump motor, and reservoir, and adjusts the brake
fluid pressure applied to each wheel cylinder
• Houses the skid control ECU
Solenoid Relay • Supplies power to each solenoid
• Housed in the skid control ECU
Motor Relay (VSC MTR Relay) • Supplies power to the pump motor
• Installed in engine room No. 1 relay block
Fail-safe Relay (VSC FAIL Relay) • Cuts off power to the motor when the pump motor circuit
malfunctions
• Installed in engine room No. 1 relay block

BC–20BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEM
BC
HINT:
*1: w/ Downhill assist control
*2: for 2WD w/ AUTO LSD
Steering Sensor • Detects the steering extent and direction and sends
signals to the skid control ECU via CAN communication
• Has a magnetic resistance element which detects the
rotation of the magnet housed in the detection gear in
order to detect the changes in magnetic resistance and
the steering amount and direction
Yaw Rate and Deceleration Sensor • Yaw rate sensor detects the vehicle's angular velocity
(yaw rate) in the vertical direction based on the extent
and direction of the deflection of the piezoelectric
ceramics
• Deceleration sensor measures the capacity of the
condenser that changes the distance between the
electrodes depending on G force, which occurs when
the vehicle is accelerated, and converts the measured
value into electrical signals
• Sends signals to the skid control ECU via CAN
communication
Master Cylinder Pressure Sensor • Detects the brake fluid pressure in the master cylinder
• Housed in the ABS and TRACTION actuator
ECM• Controls the engine output when TRC and VSC are
operating with the skid control ECU via CAN
communication
Downhill Assist Control switch*1 Allows the driver to turn downhill assist control ON and OFF
AUTO LSD switch*2 Allows the driver to turn AUTO LSD ON and OFF
Combination Meter ABS Warning Light • Illuminates to inform the driver that a malfunction in the
ABS has occurred
• Blinks to indicate DTCs that relate to the ABS
VSC Warning Light • Illuminates to inform the driver that a malfunction in the
VSC system has occurred
• Blinks to indicate DTCs that relate to the VSC
Brake Warning light • Illuminates to inform the driver that the parking brake is
ON when the system is normal, and when the brake
fluid has decreased
• Illuminates to inform the driver that a malfunction in the
EBD has occurred
Slip Indicator Light • Blinks to inform the driver that TRC, VSC, downhill
assist control and hill-start assist control are operating
• Illuminates to inform the driver that a malfunction has
occurred in the TRC or VSC system
AUTO LSD Indicator Light*2 Lights up to inform the driver when AUTO LSD operation is
possible
Downhill Assist Control Indicator
Light*1Lights up to inform the driver when downhill assist control
operation is possible
Skid Control Buzzer • Intermittently sounds to inform the driver that the VSC is
operating
• Housed in the combination meter Components Functions

BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEMBC–27
BC
3. PREFORM ZERO POINT CALIBRATION OF YAW
RATE AND DECELERATION SENSOR (When Using
Intelligent Tester)
NOTICE:
• While obtaining the zero point, do not vibrate the
vehicle by tilting, moving or shaking it and keep it
stationary. (Do not start the engine.)
• Perform this on a level surface (with an inclination
of less than 1
).
(a) Procedures for Test Mode.
(1) Check that the shift lever is in the P position and
apply the parking brake.
NOTICE:
DTCs C1210/36 and C1336/39 will be
recorded if the shift lever is not the P
position (see page BC-88).
(2) Connect the intelligent tester (with CAN VIM) to
the DLC3.
(3) Turn the ignition switch ON.
(4) Set the intelligent tester to test mode (select
"Test Mode").
HINT:
Refer to the intelligent tester operator's manual
for further details.
(b) Obtain the zero point of the yaw rate and
deceleration sensor.
(1) Keep the vehicle stationary on a level surface for
2 seconds or more.
(2) Check that the VSC warning light blinks as
shown in the illustration.
HINT:
• If the VSC warning light does not blink,
perform the zero point calibration again.
• The zero point calibration is performed only
once after the system enters test mode.
• Calibration cannot be performed again until
the stored data is cleared once.
(3) Turn the ignition switch OFF.
B127989E01
C106532
C108848E14

BC–28BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEM
BC
4. CLEAR ZERO POINT CALIBRATION DATA (When not
Using Intelligent Tester)
(a) Clear the zero point calibration data.
(1) Turn the ignition switch ON.
(2) The warning light and indicator light come on for
3 seconds to indicate that the initial check is
completed.
(3) Using SST, connect and disconnect terminals 12
(TS) and 4 (CG) of the DLC3 4 times or more
within 8 seconds.
SST 09843-18040
(4) Check that the VSC warning light comes on.
(5) Remove SST from the terminals of the DLC3.
(6) Using a check wire, perform the zero point
calibration of the yaw rate and deceleration
sensor.
CAUTION:
If the ignition switch is turned ON for more
than 15 seconds with the shift lever in the P
position after zero point of the yaw rate and
acceleration sensor has been cleared, only
the zero point of the yaw rate sensor will be
stored. If the vehicle is driven under this
condition, the skid control ECU will
recognize that zero point calibration of the
acceleration sensor is not completed and will
indicate that there is a malfunction in the
VSC system using the indicator light.
5. PERFORM ZERO POINT CALIBRATION OF YAW
RATE AND DECELERATION SENSOR (When not
Using Intelligent Tester)
NOTICE:
• While obtaining the zero point, do not vibrate the
vehicle by tilting, moving or shaking it and keep it
stationary. (Do not start the engine.)
• Perform this on a level surface (with an inclination
of less than 1
).
(a) Procedures for Test Mode.
(1) Turn the ignition switch OFF.
(2) Using SST, connect terminals 12 (TS) and 4
(CG) of the DLC3.
SST 09843-18040
(3) Check that the shift lever is in the P position and
apply the parking brake.
NOTICE:
DTCs C1210/36 and C1336/39 will be
recorded if the shift lever is not the P
position (see page BC-88).
(b) Obtain the zero point of the yaw rate and
deceleration sensor.
(1) Turn the ignition switch ON.
(2) Keep the vehicle stationary on a level surface for
2 seconds or more.
H100769E03
H100769E03

BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEMBC–29
BC
(3) Check that the VSC warning light blinks as
shown in the illustration.
HINT:
• If the VSC warning light does not blink,
perform the zero point calibration again.
• The zero point calibration is performed only
once after the system enters test mode.
• Calibration cannot be performed again until
the stored data is cleared once.
(4) Turn the ignition switch OFF.
C108848E14

BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEMBC–31
BC
(8) Check that the ABS warning light and VSC
warning light blink as shown in the illustration.
HINT:
If the ABS warning light and VSC warning
warning light do not blink, check the TS and CG
terminal circuit, and ABS and VSC warning light
circuits.
(9) Start the engine.
(b) w/ 16-inch disc only:
Check the lost booster pressure judgment and
perform the master cylinder pressure sensor zero
point calibration.
NOTICE:
Preform the check in the lost booster pressure
state (negative pressure in the booster is
depressurized).
(1) Turn the ignition switch ON.
(2) Check that the brake warning light comes on
when depressing the brake pedal with a force of
59 N (6 kgf, 13.2 lbf) or more for 1 second or
more. (The lost booster pressure state is judged
normal.)
(3) Start the engine depressing the brake pedal with
a force of 59 N (6 kgf, 13.2 lbf) or more for 1
second or more.
(4) Check that the brake warning light goes off when
quickly releasing the brake pedal. (The lost
booster pressure state is judged normal.)
(5) Leave the vehicle for 1 second or more. (Master
cylinder pressure sensor zero point calibration.)
NOTICE:
• If you slowly depress the brake pedal or
depress it again, master cylinder pressure
sensor zero point calibration is not
performed normally.
• If the lost booster pressure judgment
check is not completed normally, the
master cylinder pressure sensor check is
not judged.
• If a recheck is performed after the engine
has started, end the Test Mode, enter Test
Mode again, and release the vacuum in
the booster by pumping the brake pedal
prior to the recheck.
C108848E14
Section Title See procedure
ABS Warning Light does not Come ONBC-138
VSC Warning Light does not Come ONBC-142
TS and CG Terminal CircuitBC-177