traction control TOYOTA LAND CRUISER 1998 Factory Repair Manual

2004 LAND CRUISER (EWD548U)
9 B
The ºCurrent Flow Chartº section, describes which parts each power source (fuses, fusible links, and circuit breakers)
transmits current to. In the Power Source circuit diagram, the conditions when battery power is supplied to each system
are explained. Since all System Circuit diagrams start from the power source, the power source system must be fully
understood.
ACC
S 26
652
22
Battery30A AM2
StarterShort Pin
100A ALT Fusible Link Block
60A ABS10A ECU-B
7.5A DOME
15A EFI
10A HAZARD
20A RADIO NO.1
10A HORN
20A
10AFusePage
214
230
11 2
122 194
187
180
166
210 ABS
Cigarette Lighter
Combination Meter
Key Reminder and Seat Belt Warning
Light Auto Turn Off
Theft Deterrent and Door Lock ControlABS and Traction Control
Cruise Control
Electronically Controlled Transmission
Multiplex Communication System STOPSystem
DOMEHeadlight
Interior Light
3 EA2 1 EA1E 6
E 7
E 7
2
2
2
2 2
2 2
2 INJECTION Relay
STARTER Relay B
B
B B-O
1
1 2
23
4
3
4W-B W-B
B-W
B-W E 7
E 7B
BW1.25B FL MAIN
50A MAIN
7.5A AM2
15A HAZ-RADIO 2
22
2
2W
WEB1
EB17
6
W-RI 2 I 2 I 2
WW
W W W
1 1
1 140A DOOR LOCK CB
7.5A DOME 1W-L
R 1
1
2
431
1 1
1
111 G
G
W-R 15A TAIL
20A DEFOG
B-Y 84
32Ignition SW I 8
B-Y
11P-L Battery
15A RAD CIG2
TAIL
Relay
Power Source J POWER SOURCE (Current Flow Chart)
Engine Room R/B (See Page 20)
2
W W
B B B B B
W-R
WW W
G-WAM2
AM1 IG2
IG1W
W
The chart below shows the route by which current flows from the battery to each electrical source
(Fusible Link, Circuit Breaker, Fuse, etc.) and other parts.
*The system shown here is an EXAMPLE ONLY. It is different to the actual circuit shown in the SYSTEM CIRCUITS SECTION.

*The titles given inside the components are the names of the terminals (terminal codes) and are not treated as being
abbreviations.
2004 LAND CRUISER (EWD548U)
17 ABBREVIATIONS D
ABBREVIATIONS
The following abbreviations are used in this manual.
A/C = Air Conditioning
A/T = Automatic Transmission
ABS = Anti-Lock Brake System
ACIS = Acoustic Control Induction System
BA = Brake Assist
DIFF. = Differential
DVD = Digital Versatile Disc
EC = Electrochromic
ECU = Electronic Control Unit
ESA = Electronic Spark Advance
ETCS-i = Electronic Throttle Control System-intelligent
EVAP = Evaporative Emission
IC = Integrated Circuit
J/B = Junction Block
LH = Left-Hand
R/B = Relay Block
RH = Right-Hand
SFI = Sequential Multiport Fuel Injection
SRS = Supplemental Restraint System
SW = Switch
TEMP. = Temperature
TRAC = Traction Control
VSC = Vehicle Stability Control
VSV = Vacuum Switching Valve
w/ = With
w/o = Without

2004 LAND CRUISER (EWD548U)
234VSC
1. ABS Operation
If the brake pedal is depressed suddenly, the ABS controls the hydraulic pressure of the wheel cylinders for all the four
wheels to automatically avoid wheel locking and ensure the directional and steering stability of the vehicle. If the brake pedal
is depressed suddenly, the ABS & BA & TRAC & VSC ECU controls the solenoids in the actuators using the signals from the
sensors to move the brake fluid to the reservoir in order to release the braking pressure applied to the wheel cylinder. If the
ABS & BA & TRAC & VSC ECU detects that the fluid pressure in the wheel cylinder is insufficient, the ECU controls the
solenoids in the actuators to increase the braking pressure.
2. Traction Control Operation
The traction control system controls the engine torque, the hydraulic pressure of the driving wheel cylinders, slipping of the
wheels which may occur at start or acceleration of the vehicle, to ensure an optimal driving power and vehicle stability
corresponding to the road conditions.
3. VSC Operation
Unexpected road conditions, vehicle speed, emergency situation, and any other external factors may cause large under- or
over-steering of the vehicle. If this occurs, the VSC system automatically controls the engine power and wheel brakes to
reduce the under- or over-steering.
To reduce large over-steering :
If the VSC system determines that the over-steering is large, it activates the brakes for the outer turning wheels depending
on the degree of the over-steering to produce the moment toward the outside of the vehicle and reduce the over-steering.
To reduce large under-steering :
If the VSC system determines that the under-steering is large, it controls the engine power and activates the rear wheel
brakes to reduce the under-steering.
VSC indicator light
If an error occurs in the VSC system, the VSC indicator lights up to warn the driver.
4. Traction Mode and VSC Function
When the center differential of the transfer is locked, the VSC function is turned off. At this time, the VSC OFF indicator light
in the combination meter will come on, and informs the driver that the VSC function is OFF.
5. Mutual System Control
To efficiently operate the VSC system at its optimal level, the VSC system and other control systems are mutually controlled
while the VSC system is being operated.
Engine throttle control
The engine power does not interfere with the VSC brake control by controlling the opening of the throttle and reducing the
engine output.
Engine control and electronically controlled transmission control
The strong braking force does not interfere with the braking force control of the VSC system by turning off the accel. and
reducing changes in the driving torque at shift-down.
VSC system operation indication
The slip indicator light flashes and the buzzer sounds intermittently to warn the driver that the current road is slippery, while
the VSC system is being operated.
6. Fail Safe Function
If an error occurs in the ABS & BA & TRAC & VSC ECU, sensor signals, and/or actuators, the ABS & BA & TRAC & VSC
ECU inhibits the brake actuator control and inputs the error signal to the engine control module. According to the error signal,
the brake actuator turns off the solenoid and the engine control module rejects any electronically controlled throttle open
request from the VSC system. As a result, the vehicle functions without the ABS, BA, TRAC, and VSC systems.
System Outline

B04201
B04202
- INTRODUCTIONFOR ALL OF VEHICLES
IN-21
21 Author
: Date
:
2004 LAND CRUISER (RM1071U)
(b) Using Braking Tester:
Measure by low-speed type (Vehicle Speed: Below 0.5
km/h or 0.3 mph) brake tester and observe the following
instructions before performing the test.
(1) Position the wheels to be tested (front or rear) on
the tester.
(2) Put the center differential in FREE position.
(3) If the vehicle is equipped with Vehicle Skid Control
(VSC) system, prohibit the system from the activa-
tion (See step 2.).
(4) Shift the transmission shift lever to ºNº position.
HINT:
Do not forget to change the Vehicle Skid Control (VSC) & Trac-
tion Control (TRAC) system to operational condition after the
test. Check that the VSC warning indicator light goes off when
restarting the engine.
(c) Using Speedometer Tester:
Observe the following instructions and then measure with
the rear wheels.
(1) Position the rear wheels on the tester roller.
(2) Position the front wheels on the free roller or jack
them up.
(3) Put the center differential in FREE position.
(4) If the vehicle is equipped with Vehicle Skid Control
(VSC) & Traction Control (TRAC) system, prohibit
the system from the activation (See step 2.).
(5) Ensure that the vehicle does not move using wires.
CAUTION:
The maximum speed should be less than 60 km/h (37 mph)
and maximum driving time should be 1 minute.
HINT:
Sudden shifting, braking, acceleration or deceleration is
not allowed.
Do not forget to change the Vehicle Skid Control (VSC) &
Traction Control (TRAC) system to operational condition
after the test. Check that the VSC warning indicator light
goes off when restarting the engine.

B04203
B04204
IN-22
- INTRODUCTIONFOR ALL OF VEHICLES
22 Author
: Date
:
2004 LAND CRUISER (RM1071U)
(d) Using Chassis Dynamometer:
Observe the following instructions and then measure with
the rear wheels.
(1) Remove the front propeller shaft.
(2) Put the center differential in LOCK position.
(3) If the vehicle is equipped with Vehicle Skid Control
(VSC) & Traction Control (TRAC) system, prohibit
the system from the activation (See step 2.).
(4) Ensure that the vehicle is securely fixed.
HINT:
Sudden shifting, braking, acceleration or deceleration is
not allowed.
Do not forget to change the Vehicle Skid Control (VSC) &
Traction Control (TRAC) system to operational condition
after the test. Check that the VSC warning indicator light
goes off when restarting the engine.
(e) On-V ehicle Wheel Balancing:
When doing on-vehicle wheel balancing on a full-time
4WD vehicle, to prevent each wheel from being rotated at
different speed in different directions (which could dam-
age the center differential), always be sure to observe the
following precautions.
(1) All of 4 wheels should be jacked up, being apart
from the ground completely.
(2) Put the center differential in LOCK position.
(3) If the vehicle is equipped with Vehicle Skid Control
(VSC) & Traction Control (TRAC) system, prohibit
the system from the activation (See step 2.).
(4) The parking brake lever should be fully released.
(5) None of the brakes should be applied.
(6) The wheels should be driven on the wheel balancer
with the engine running.
(7) Carry out the wheel balancing with the transmission
position in D position.
HINT:
When doing this balancing, pay attention to the other
wheels rotating at the same time.
Sudden acceleration, deceleration or braking is not al-
lowed.
Do not forget to change the Vehicle Skid Control (VSC) &
Traction Control (TRAC) system to operational condition
after the test. Check that the VSC warning indicator light
goes off when restarting the engine.

B04205
Conditions
Towing Method
1. Flat Bed TruckParking Brake
Any Position
2. Wheel Lift Type TruckAppliedTransmission Shift Lever
Position
Applied
From RearAny Position From Front
B04206
NO


NOIf this towing method is used, either from the front or rear:
Never tow the vehicle using a method where the lifted-up wheel
cannot rotate.
Do not use the sling type towing method, either from the front or rear,
as this method causes damage to the body. (a) There is a danger of the drive train heating up and causing break-
down, or of the wheels flying off the dolly.
(b) In addition, if the vehicle is equipped with the Vehicle Skid Control
(VSC) & Traction Control (TRAC) system, the system will apply the
rotating wheels brake unless the engine isn't shut off.
- INTRODUCTIONFOR ALL OF VEHICLES
IN-23
23 Author
: Date
:
2004 LAND CRUISER (RM1071U)
5. WHEN TOWING FULL-TIME 4WD VEHICLES
Use one of the methods shown below to tow the vehicle.
If the vehicle has trouble in the chassis and drive train, use method 1 (flat bed truck).
NOTICE:
Do not use any towing method other than those shown above.
For example, the towing methods shown below are dangerous or damage the vehicle, so do not use
them.