2001 TOYOTA SEQUOIA brake

DIDDE±01
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±727
921 Author: Date:
2005 SEQUOIA (RM1146U)
DATA LIST / ACTIVE TEST
1. DATA LIST
HINT:
By accessing the DATA LIST displayed by the hand±held tester, you can read the value of the switches and
sensors and so on without removing any parts. Reading the DATA LIST is the first step of troubleshooting
and is one method to shorten labor time.
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Following the display on the tester, read the DATA LIST.
AIR SUSPENSION:
ItemMeasurement Item / Range (Dis-
play)Normal ConditionDiagnostic Note
VEHICLE SPD
Vehicle speed reading / min.: 0
km/h (0 mph), max.: 255 km/h
(158 mph)
Actual vehicle speedSpeed indicated on the combina-
tion meter
FR WHEEL SPD
Wheel speed (Front right) reading /
min.: 0 km/h (0 mph), max.: 255
km/h (159 mph)
Actual vehicle speedSpeed indicated on the speedome-
ter
FL WHEEL SPD
Wheel speed (Front left) reading /
min.: 0 km/h (0 mph), max.: 255
km/h (159 mph)
Actual vehicle speedSpeed indicated on the speedome-
ter
IG VOLTAGEECU power supply voltage / min.:
0 V, max.: 25.5 VActual ECU power supply voltage:
10 to 14 V±
POWER VOLTAGE+B power source voltage / min.: 0
V, max.: 25.5 VActual battery power supply volt-
age: 10 to 14 V±
STEERING ANG
Steering angle sensor reading /
min.: ±49150.5 deg, max.: 49152
degActual steering angle /
Left turn: reading increases
Right turn: reading increasesZero point is set at the point when
battery is connected
ENGINE SPDCrankshaft position sensor read-
ing / min.: 0 rpm, max.: 25,500 rpmActual engine speedSpeed indicated on the combina-
tion meter
HEIGHT SW DOWNHeight control switch (DOWN) /
ON or OFFON: Height control switch
ºDOWNº button pressed
OFF: ±
±
HEIGHT SW UPHeight control switch (UP) / ON or
OFFON: Height control switch ºUPº
button pressed
OFF: ±
±
HEIGHT SW HOLDHeight control mode select switch
/ ON or OFFON: Height control mode select
switch pressed
OFF: ±
±
STOP LIGHT SWStop light switch / ON or OFFON: Brake pedal depressed
OFF: Brake pedal released±
DOOR SWDoor courtesy light switch / ON or
OFFON: Open each door
OFF: Close all doors±
L4 SW4LO switch / ON or OFFON: 2WD/4HI switch pressed
OFF: ±±
TSTS terminal / ON or OFFON: During test mode
OFF: Normal mode±
TCTC terminal / ON or OFFON: DTC recorded
OFF: No DTC recorded±
SOL SLRLHeight control valve solenoid (Lev-
elling solenoid valve) / ON or OFFON: Leveling solenoid operated
OFF: Leveling solenoid not oper-
ated
±
SOL SLRGHeight control valve solenoid
(Gate solenoid valve) / ON or OFFON: Gate solenoid operated
OFF: Gate solenoid not operated±

F19446
W
41G±Y1
4A11
4AG±Y27
S25 STP
BatteryB ALT
85 W 1
1L STOP 2
1FS14
Stop Light Switch
Sub J/B No. 4Suspension Control
ECU
Instrument Panel J/BF10
Fusible Link Block
1L
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±767
961 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1782/82 Stop Light Switch Circuit (Test Diagnosis)
CIRCUIT DESCRIPTION
When the brake pedal is depressed, the stop light comes on and the signal is input to the STP terminal of
the suspension control ECU.
HINT:
This DTC is output only when the sensor signal check is done.
DTC No.DTC Detecting ConditionTrouble Area
C1782/82The signal from the stop light switch assy does not change.

Stop light switch assy

Stop light switch circuit

Suspension control ECU
WIRING DIAGRAM
DIDE7±01

F16805
Wire Harness View:
S25
STP
DI±768
± DIAGNOSTICSAIR SUSPENSION SYSTEM
962 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Inspect stop light.
CHECK:
Check that the stop light comes on when the brake pedal is depressed and goes off when the brake pedal
is released.
OK:
Stop light operates normally.
NG Go to step 3.
OK
2 Inspect suspension control ECU.
PREPARATION:
Disconnect the ECU connector.
CHECK:
Measure the voltage between terminal S25±27 (STP) of the
suspension control ECU and body ground when the stop light
switch is ON and OFF.
OK:
Switch conditionSpecified condition
Brake pedal depressed (ON)10 to 14 V
Brake pedal released (OFF)Below 1 V
NG Repair or replace harness connector.
OK
Replace suspension control ECU
(See page IN±35).

I21525
Free Pushed in
F16805
Wire Harness View:
S25
STP
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±769
963 Author: Date:
2005 SEQUOIA (RM1146U)
3 Inspect stop light switch assy.
PREPARATION:
Disconnect the stop light switch assy connector.
CHECK:
Check resistance between terminals 1 and 4 of the stop light
switch assy.
OK:
Switch conditionTester connectionSpecified condition
Switch pin free1 ± 4Below 1 W
Switch pin pushed in1 ± 410 kW or higher
NG Replace stop light switch assy.
OK
4 Inspect suspension control ECU.
PREPARATION:
Disconnect the ECU connector.
CHECK:
Measure the voltage between terminal S25±27 (STP) of the
suspension control ECU and body ground when the stop lamp
switch is ON and OFF.
OK:
Switch conditionSpecified condition
Brake pedal depressed (ON)10 to 14 V
Brake pedal released (OFF)Below 1 V
NG Repair or replace harness connector.
OK
Replace suspension control ECU
(See page IN±35).

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

DIDLW±01
F19153
Speed Sensor
(Each Wheel)
Stop Lamp Switch
Parking Brake Switch
Delta S Sensor
Yaw Rate
(Deceleration) SensorABS & VSC Actuator
Skid Control
ECUCombination
Meter
Translate
ECUSteering Angle
Sensor
4WD ECU
ECM
CAN Communication SystemAir Suspension ECU (*1): CAN1 Circuit
(*2): CAN2 Circuit
(*3): Vehicle CAN Circuit(*2)
(*3) (*1)
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±893
1087 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DIAGRAM

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