2001 TOYOTA SEQUOIA warning

DIDLV±01
F17996
Front Speed SensorABS & VSC Actuator
(w/ Skid Control ECU)Level Warning Switch
Rear Speed Sensor Rear Speed Sensor Rotor
Front Speed
Sensor Rotor
Parking Brake SwitchStop Light Switch
Center Diff. Lock Switch *1
TRAC OFF Switch *2
Steering Angle Sensor
DLC3Brake Inhibit RelayTranslate ECU
VSC BuzzerBrake Booster
(Including Active Brake Booster
Solenoid, Delta S Sensor and Boost-
er Pedal Switch)
Master Cylinder
Pressure Sensor
Front Speed Sensor Rotor
Front Speed Sensor
Yaw Rate Sensor
(Including Deceleration Sensor)
ABS Warning Light
VSC TRAC Warning light
VSC OFF Indicator Light *
1
TRAC OFF Indicator Light *2
BRAKE Warning Light
SLIP Indicator Light
*1: Only for 4WD
*2: Only for 2WDCenter Diff. Lock
Position Switch
DI±892
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1086 Author: Date:
2005 SEQUOIA (RM1146U)
LOCATION

DIDLX±01
DI±894
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1088 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DESCRIPTION
1. SYSTEM DESCRIPTION
HINT:

The yaw rate sensor and deceleration sensor are combined and in a single unit. This unit communi-
cates with the skid control ECU through the CAN communication system.

No changes have been made to the communication method between the VSC system and ECM. How-
ever, the communication method between the Translate ECU and ECM has been changed from serial
to CAN communication.
(a) ABS
(Anti±lock Brake System)
The ABS helps prevent the wheels from locking when the brakes are applied firmly or when braking
on a slippery surface.
(b) EBD
(Electronic Brake force Distribution)
The EBD control utilizes ABS, realizing proper brake force distribution between front and rear wheels
in accordance with driving conditions.
In addition, during braking while cornering, it also controls the brake forces of the right and left wheels,
helping to maintain vehicle behavior.
(c) BA (Brake Assist)
The primary purpose of the brake assist system is to provide an auxiliary brake force to assist the driver
who cannot generate a large enough brake force during emergency braking, thus helping to maximize
the vehicle's braking performance.
(d) TRAC
(Traction Control)
The TRAC system helps prevent the drive wheels from slipping if the driver presses down on the accel-
erator pedal excessively when starting off or accelerating on a slippery surface.
(e) VSC
(Vehicle Stability Control)
The VSC system helps prevent the vehicle from slipping sideways as a result of strong front wheel skid
or strong rear wheel skid during cornering.
2. ABS with EBD & BA & TRAC & VSC OPERATION
(a) The skid control ECU calculates vehicle stability tendency based on signals from the speed sensor,
yaw rate (deceleration) sensor and steering angle sensor. In addition, it evaluates the results of the
calculations to determine whether any control actions (control of the engine output torque by electronic
throttle control and of the wheel brake pressure by the brake actuator) should be implemented.
(b) The SLIP indicator blinks and the VSC buzzer sounds to inform the driver that the VSC system is oper-
ating. The SLIP indicator also blinks when TRAC is operating, and the operation being performed is
displayed.
3. FAIL SAFE FUNCTION
(a) When a failure occurs in the ABS & BA & TRAC & VSC systems, the ABS and VSC warning lights come
on and ABS & BA & TRAC & VSC operations are prohibited. In addition to this, when there is a failure
that disables EBD operation, the brake warning light also comes on and EBD operation is prohibited.
(b) If some control is prohibited due to a malfunction during its operation, that control will be cut off gradual-
ly not to change the stability of the vehicle suddenly.

DI93A±03
Inspector 's
Name:
Customer 's Name
Date Vehicle
Brought InRegistration DateRegistration No.
Frame No.
Odometer Reading/ /
/ /
Date Problem First Occurred
Frequency Problem Occurs/ /
ContinuousIntermittent ( times a day)
Remains ONDoes not Light Up
DTC Check1st Time
2nd TimeNormal System Code
Trouble Code (Code )
Symptomskm
miles
Check ItemNormal
ABS does not operate.
ABS does not operate efficiently.
Does not Light Up
ABS & BA & TRAC & VSC Check Sheet
VSC does not operate. (Wheels sideslip when turning sharply.)
ABS Warning Light
Abnormal
Remains ON
Does not Light Up
Remains ONDoes not Light Up
Remains ONDoes not Light Up
Remains ONDoes not Light Up
TRAC OFF Indicator
Light Abnormal*1
SLIP Indicator
Light Abnormal VSC TRAC Warning
Light Abnormal
BRAKE Warning
Light Abnormal
Malfunction
Indicator Light
TRAC does not operate. (Wheels spin when starting off rapidly.)
Remains ON
Does not Light UpVSC OFF Indicator
Light Abnormal*2
BA does not operate
Normal System Code
Trouble Code (Code )
DI±896
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1090 Author: Date:
2005 SEQUOIA (RM1146U)
CUSTOMER PROBLEM ANALYSIS CHECK
*1: Only for 2WD
*2: Only for 4WD

DIDLZ±01
F09750
DLC3Ts
CG
BR3904
0.13 sec. 0.13 sec.
ON
OFF
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±899
1093 Author: Date:
2005 SEQUOIA (RM1146U)
TEST MODE PROCEDURE
1. When not using the hand±held tester:
SENSOR CHECK (TEST MODE)
NOTICE:
When having replaced the master cylinder pressure, yaw
rate and deceleration sensors and/or the ECU, perform
zero point calibration of the master cylinder pressure, yaw
rate and deceleration sensors (See page DI±897).
HINT:
If the ignition switch is turned from the ON to the ACC or LOCK
position in test mode, test mode DTCs will be erased.
(a) Procedures for test mode:
(1) Turn the ignition switch OFF.
(2) Check that the shift lever is in the P position, and
turn the steering wheel to the neutral position.
(3) Using SST, connect terminals Ts and CG of the
DLC3.
SST 09843±18040
(4) Start the engine.
(5) Check that the ABS and VSC TRAC warning lights
blink.
HINT:
If the ABS and VSC TRAC warning lights do not blink, inspect
the ABS warning light circuit, VSC TRAC warning light circuit
and Ts terminal circuit.
(6) Keep the vehicle in a stationary condition on a level
surface for 4 sec. or more.
ABS warning light circuitDI±1021 or DI±1025
VSC TRAC warning light circuitDI±1027 or DI±1031
Ts terminal circuitDI±1057

F09750
CG TcDLC3
BR3893
Trouble Code (Example Code 72, 76)
ON
OFF
4 sec. 1.5 sec.
Repeat 2.5 sec.
0.5 sec. 0.5 sec. 0.5 sec. 0.5 sec.7726
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±901
1095 Author: Date:
2005 SEQUOIA (RM1146U)
(f) Read the DTC.
(1) Using SST, connect terminals Tc and CG of the
DLC3.
SST 09843±18040
(2) Read the number of blinks of the warning light.
HINT:

See the list of DTC (step 3).

If all sensors are normal, a normal system code is output
(A cycle of 0.25 sec. ON and 0.25 sec. OFF is repeated).

If 2 or more malfunctions are indicated at the same time,
the codes will be displayed in ascending order.
(3) After doing the check, disconnect terminals Ts and
CG, Tc and CG of the DLC3, and turn the ignition
switch OFF.
SST 09843±18040

D05981
Hand±held
Tester
DLC3
BR3904
0.13 sec. 0.13 sec.
ON
OFF
F02135
Start Position
End PositionWithin ± 5° DI±902
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1096 Author: Date:
2005 SEQUOIA (RM1146U)
2. When using the hand±held tester:
SENSOR CHECK (TEST MODE)
NOTICE:
When having replaced the master cylinder pressure, yaw
rate and deceleration sensors and/or ECU, perform zero
point calibration of the master cylinder pressure, yaw rate
and deceleration sensors (See page DI±897). Make sure
that this operation is done before performing the following.
(a) Procedures for test mode:
(1) Connect the hand±held tester to the DLC3.
(2) Check that the shift lever is in the P position, and
turn the steering wheel to the neutral position.
(3) Start the engine.
(4) Select the SIGNAL CHECK on the hand±held tes-
ter.
(5) Check that the ABS warning light and VSC TRAC
warning light blink.
HINT:
If the ABS and VSC TRAC warning lights do not blink, inspect
the ABS warning light circuit, VSC TRAC warning light circuit
and Ts terminal circuit.
(6) Keep the vehicle in a stationary condition on a level
surface for 4 sec. or more.
ABS warning light circuitDI±1021 or DI±1025
VSC TRAC warning light circuitDI±1027 or DI±1031
Ts terminal circuitDI±1057
(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 for 3 seconds.

DI±904
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1098 Author: Date:
2005 SEQUOIA (RM1146U)
3. DTC of ABS sensor check function:
Code No.DiagnosisTrouble Area
C1271 / 71Low output voltage of right front speed sensor

Right front speed sensor

Sensor installation

Sensor rotor
C1272 / 72Low output voltage of left front speed sensor

Left front speed sensor

Sensor installation

Sensor rotor
C1273 / 73Low output voltage of right rear speed sensor

Right rear speed sensor

Sensor installation

Sensor rotor
C1274 / 74Low output voltage of left rear speed sensor

Left rear speed sensor

Sensor installation

Sensor rotor
C1275 / 75Abnormal change in output voltage of right front speed sen-
sorRight front speed sensor rotor
C1276 / 76Abnormal change in output voltage of left front speed sen-
sorLeft front speed sensor rotor
C1277 / 77Abnormal change in output voltage of right rear speed sen-
sorRight rear speed sensor rotor
C1278 / 78Abnormal change in output voltage of left rear speed sensorLeft rear speed sensor rotor
C1279 / 79Deceleration sensor is faulty
Deceleration sensor

Sensor installation
C1281 / 81Master cylinder pressure sensor output signal is faultyMaster cylinder pressure sensor
HINT:
Read the number of blinks of the ABS warning light.
DTC of VSC sensor check function:
Code No.DiagnosisTrouble Area
C0371 / 71Yaw rate sensor output signal malfunction
Yaw rate sensor

Yaw rate sensor circuit
HINT:
Read the number of blinks of the VSC TRAC warning light.

DI93F±04
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±905
1099 Author: Date:
2005 SEQUOIA (RM1146U)
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.
NOTICE:

When replacing the skid control ECU, sensor, etc., turn the ignition switch OFF.

When replacing the master cylinder pressure, yaw rate and deceleration sensors and/or the
ECU, make sure to perform master cylinder pressure, yaw rate, and deceleration sensors' zero
point calibration (See page DI±897).
SymptomSuspected AreaSee page
ABS does not operate
When the following 1. to 4. are all normal and the problem
is still occurring, replace the skid control ECU.
1. Check the DTC reconfirming that the normal code is
output.
2. IG power source circuit
3. Speed sensor circuit
4. Check the hydraulic circuit for leakage.
DI±911
DI±957
DI±925
DI±1059
ABS does not operate efficiently
When the following 1. to 4. are all normal and the problem
is still occurring, replace the skid control ECU.
1. Check the DTC reconfirming that the normal code is
output.
2. Speed sensor circuit
3. Stop light switch circuit
4. Check the hydraulic circuit for leakage.
DI±911
DI±925
DI±963
DI±1059
ABS warning light abnormal
1. ABS warning light circuit
2. Skid control ECUDI±1021 or
DI±1025
BRAKE warning light abnormal
1. BRAKE warning light circuit
2. Skid control ECU
3. Translate ECUDI±1033 or
DI±1038
DTC check cannot be done
When the following 1. to 3. are all normal and the problem
is still occurring, replace the skid control ECU.
1. ABS warning light circuit
2. Tc terminal circuit
3. VSC TRAC warning light circuit
DI±1021 or
DI±1025
DI±1055
DI±1027
DI±1031
Speed sensor signal check cannot be done1. Ts terminal circuit
2. Skid control ECUDI±1057
TRAC does not operate
Only when 1. to 4. are all normal and the problem is still
occurring, replace the skid control ECU.
1. Check the DTC, reconfirming that the normal code is
output.
2. IG power source circuit
3. Check the hydraulic circuit for leakage
4. Speed sensor circuit
DI±911
DI±957
DI±1059
DI±925
TRAC does not operate efficiently
Only when 1. to 3. are all normal and the problem is still
occurring, replace the skid control ECU.
1. Check the DTC, reconfirming that the normal code is
output.
2. Check the hydraulic circuit for leakage
3. Speed sensor circuit
DI±911
DI±1059
DI±925