engine TOYOTA SEQUOIA 2001 Service Repair Manual

F19451
C6
Combination
MeterSuspension Control
ECU
I18
Ignition SW
Engine Room J/B Instrument Panel J/B B±O
W±R11
7 1H
1JIGN1
1C
1C32
B±RMAN. 24
13 LG11
S25 VN
5
IG2 AM2 6
W±R
B
Battery 1
2D AM2
2C1
B5 4F10
FL Block
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±789
983 Author: Date:
2005 SEQUOIA (RM1146U)
Height Control Manual Indicator Lamp Circuit
CIRCUIT DESCRIPTION
When manual mode is selected by pressing the height control mode select switch, the manual indicator lamp
comes on. (For the wiring diagram of the height control mode select switch circuit, see page DI±778.) If the
suspension control ECU detects a problem, the height control manual indicator lamp blinks while suspend-
ing the height control function. At the same time, the suspension control ECU records a DTC in the memory.
Connect terminals TC and CG of the DLC3 to make the height control manual indicator lamp blink and output
DTCs.
WIRING DIAGRAM
DIDEN±01

F19174
Combination MeterTire Pressure
Monitor ECU
Engine Room J/B I18
Ignition SW IGN1
B±O
IG2 AM2 1C11
Battery 2
1H
T17 C5GR±L
Tire Pressure
B±R
B 56
54AM2 24
6IND Instrument Panel J/B
C620
2D1
2C1 1C3
1J7
F10
Fusible Link BlockInstrument Panel J/B
W±R
W±R
B
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
DI±873
1067 Author: Date:
2005 SEQUOIA (RM1146U)
Tire Pressure Warning Lamp Circuit
CIRCUIT DESCRIPTION
If the ECU detects trouble, the tire pressure warning lamp comes on and tire pressure monitor is cancelled
at the same time. At this time, the ECU records a DTC in memory.
Connect terminals Tc and CG of the DLC3 to make the tire pressure warning lamp blink and output the DTC.
WIRING DIAGRAM
DIDKF±01

F19790
Combination MeterTire Pressure
Monitor ECU
Engine Room J/B I18
Ignition SWIGN1
B±O
IG2AM2 1C11
Battery 2
1HT17
C5GR±L
Tire Pressure
B±R
B 56
54AM2 24
6IND Instrument Panel J/B
C620
2D1
2C1 1C3
1J7
F10
Fusible Link BlockInstrument Panel J/B
W±R
W±R
B
T17 T18 Tire Pressure
Warning Reset SW
G±R
CALSW
GND
T17 1H
1H
1F7
1 10
W±B11 10 Instrument Panel J/B
W±B
A J8
J/C
IE1 2
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
DI±875
1069 Author: Date:
2005 SEQUOIA (RM1146U)
Tire Pressure Warning Reset Switch Circuit
CIRCUIT DESCRIPTION
Receiving the signal from the tire pressure warning reset switch, the tire pressure monitor ECU indicates the
initialization of the pressure warning system.
WIRING DIAGRAM
DIDKG±01

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.

DIDLY±01
F09750
DLC3
Ts
Tc
CG
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±897
1091 Author: Date:
2005 SEQUOIA (RM1146U)
CALIBRATION
1. ZERO POINT CALIBRATION OF MASTER CYLINDER
PRESSURE, YAW RATE AND DECELERATION SEN-
SORS
HINT:
When having replaced the master cylinder pressure, yaw rate
and deceleration sensors and/or the ECU, make sure to per-
form master cylinder pressure, yaw rate and deceleration sen-
sors' zero point calibration.
NOTICE:

While obtaining the zero point, do not vibrate the ve-
hicle by tilting, moving or shaking it and keep it in a
stationary condition. (Do not start the engine.)

Be sure to do this on a level surface (within an inclina-
tion of 1 degree).
(a) Perform master cylinder pressure, yaw rate and decelera-
tion sensors zero point calibration.
(1) Using SST, connect terminals Ts and CG of the
DLC3.
SST 09843±18040
(2) Shift the shift lever to the P position.
(3) Turn the ignition switch to the ON position.
(4) Keep the vehicle in a stationary condition on a level
surface for 4 sec. or more.
(5) Keep your foot off the brake pedal.
Do not leave 4WD vehicles in the L4 position.
(6) Press the center diff. lock (TRAC OFF) switch 3
times within 3 seconds.
(7) Check that the VSC buzzer sounds for 3 seconds.
HINT:

If the VSC buzzer does not sound, do the zero point cal-
ibration again and/or check the VSC buzzer circuit (See
page DI±1052).

If the VSC buzzer does not sound, check for yaw rate and
deceleration sensor failure (See page DI±911).
(8) Turn the ignition switch OFF.
(9) Disconnect terminals Ts and CG of the DLC3.
(b) Perform steering angle sensor zero point calibration.
This calibration is carried out automatically by following
procedures below:
(1) Make sure the system is not in sensor check mode.
(2) Calibrate the steering angle sensor by driving the
vehicle in a straight line at more than 7 MPH (12
km/h) for 5 seconds.

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

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±922
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
111 6 Author: Date:
2005 SEQUOIA (RM1146U)
*1: As long as the following operations are not performed, the ABS warning light will not go OFF only by re-
pairing the trouble area.
(1) Drive the vehicle at 12 mph (20 km/h) for 30 seconds or more and check that the ABS warning light goes
off.
(2) Clear the DTC (See page DI±911).
HINT:
There is a possibility that the hand±held tester cannot be used when the ABS warning light is always ON.
DTC chart of VSC system:
DTC No.
(See Page)Detection ItemTrouble Area
C1201/51
(DI±936)Engine control system malfunction
Engine control system
C1202/52
(DI±937)Brake fluid level warning switch circuit

Brake fluid level

Brake fluid level warning switch

Brake fluid level warning switch circuit

Skid control ECU

CAN1 communication system

Translate ECU
C1203/53 *1
(DI±942)Malfunction in CAN1 communication

Skid control ECU

CAN1 communication system

ECM

Translate ECU
C1207/37
(DI±522)Reverse gear signal failureECT
C1223/43
(DI±945)Malfunction in ABS control systemABS control system
C1231/31
(DI±946)Malfunction in steering angle sensor

Steering angle sensor

Steering angle sensor communication circuit

Skid control ECU

Translate ECU

CAN communication system
C1232/32
(DI±951)Malfunction in deceleration sensor
Yaw rate (deceleration) sensor

Yaw rate (deceleration) sensor circuit
C1234/34
(DI±954)Malfunction in yaw rate sensor
Yaw rate (deceleration) sensor

Yaw rate (deceleration) sensor circuit
C1310/11
(DI±969)Open or short circuit in active brake booster solenoid circuit
Brake booster

Active brake booster solenoid circuit
C1311/12
(DI±971)Open or short circuit in brake inhibit relay circuit
Brake inhibit relay

Brake inhibit relay circuit
1335/35
(DI±946)Malfunction in steering angle sensor communication circuit

Steering angle sensor

Steering angle sensor communication circuit

Skid control ECU

Translate ECU

CAN1 communication system
C1340/47*2
(DI±977)Center diff. lock circuit malfunction

Center diff. lock position switch

Center diff. lock position switch circuit

Center diff. lock indicator light circuit

Translate ECU
C1360/61
(DI±983)Malfunction in master cylinder pressure sensor
Master cylinder pressure sensor

Master cylinder pressure sensor circuit

DI±936
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1130 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1201 / 51 Engine Control System Malfunction
CIRCUIT DESCRIPTION
If trouble occurs in the engine control system, the ECM transmits the abnormality to the skid control ECU
via translate ECU. The skid control ECU sets this DTC and the skid control ECU prohibits TRAC and VSC
control.
DTC No.DTC Detecting ConditionTrouble Area
C1201 / 51
Conditions 1. and 2. continue for 5 sec.:
1. Engine speed: 500 rpm or more.
2. A trouble signal of the engine control system is input.

Engine control system
INSPECTION PROCEDURE
1 Check engine control system.
CHECK:
Check engine control system (See page DI±43).
RESULT:
DTC is not outputA
DTC is outputB
B Check and repair engine control system
(See page DI±9).
A
Replace ECM (See page SF±80).
DIDM6±01

F19769
Translate ECU
VSC+
VSC±
IG17
T5
T511
1
T5B±RL
W
AA
J37
J38
A
J37B±R J/C
B±R B±RL
W 7
IL2
6
IL2
1
IL16
S1
2
S1
13
S1 ABS &VSC Actuator
(Skid Control ECU)
CANH
CANL
IG1
8
3C8
3A
B±R Instrument Panel J/B
4
1C
2
1C
3
1C
6
1C4
1F
11
1H
7
1J
1
1L ECU±IG
IGN1
AM1 B±R B±Y
W±R
W±LB±O
W±R
W
1 2Combination Meter
24
C6
Brake
1C5 W
8
ALTF10 Fusible
Link BlockEngine Room J/B
A W±R 1
2D1
2C
4
5
R±B R±B
B1 Brake Fluid Level
Warning SW
Y±L Y±LW±B 23
IA1
129
IA5O
A
A O
OJ43
J/C
IG Sub J/B No.4
LG±R
LG±R 4
4B4
4D
1P2 Parking
Brake SW
B
Battery 39
T5
24
T5
40
T5
4
T5 BRL
LVL2
GND
PKB2Sub J/B No.3
I18
Ignition SW
AM1 IG1
AM2 IG2 1
5 W±L
2
6
AM2
BB±R (CAN1 Circuit)
(CAN1 Circuit) DI±938
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1132 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM