Page 1349 of 2000

GF1A TRANSFER – ACTIVE TORQUE CONTROL 4WD SYSTEMTF–21
TF
DATA LIST / ACTIVE TEST
1. READ DATA LIST
HINT:
Using the intelligent tester's (with CAN VIM) DATA LIST
allows switch, sensor and other item values to be read
without removing any parts. Reading the DATA LIST
early in troubleshooting is one way to save time.
(a) Connect the intelligent tester (with CAN VIM) to the
DLC3.
(b) Turn the ignition switch ON.
(c) Read the DATA LIST according to the display on the
tester.
4WD control ECU
Item Measurement Item/Range
(Display)Normal Condition Diagnostic Note
4WD WARN LAMP 4WD indicator light /OFF or ON OFF: 4WD indicator light OFF
ON: 4WD indicator light ON-
SLIP INDI LAMP Slip indicator light /OFF or ON OFF: SLIP indicator light OFF
ON: SLIP indicator light ON-
STOP LAMP SW Stop light switch /OFF or ON OFF: Brake pedal released
ON: Brake pedal depressed-
STEERING ANGLE Steering angle value /
Min.: -3276.8 deg
Max.: 3276.7 degMin.: -3276.8 deg
Max.: 3276.7 deg-
FR WHEEL SPD FR wheel speed /
Min.: 0 km/h (0 mph)
Reading : Max.: 326.4 km/h
(202.8 mph)Actual wheel speed Almost no difference from the
speedometer
FL WHEEL SPD FL wheel speed /
Min.: 0 km/h (0 mph)
Reading : Max.: 326.4 km/h
(202.8 mph)Actual wheel speed Almost no difference from the
speedometer
RR WHEEL SPD RR wheel speed /
Min.: 0 km/h (0 mph)
Reading : Max.: 326.4 km/h
(202.8 mph)Actual wheel speed Almost no difference from the
speedometer
RLWHEEL SPD RL wheel speed /
Min.: 0 km/h (0 mph)
Reading : Max.: 326.4 km/h
(202.8 mph)Actual wheel speed Almost no difference from the
speedometer
AMBI TEMP Ambient temperature /
Min.: -128
C (198.4 F)
Max.: 127 C (260.6 F)Min.: -128 (198.4
F)
Max.: 127 (260.6
F)-
COOLANT TEMP Engine coolant temperature /
Min.: 0
C (32 F)
Max.: 127.5
C (261.5 F)Min.: 0
C (32 F)
Max.: 127.5 C (261.5 F)-
LOCK SW 4WD lock switch / OFF or ON OFF: 4WD lock switch off
ON: 4WD lock switch on-
SLC CUR SLC solenoid (4WD linear
solenoid) current /
Min.: 0 A
Max.: 3 AMin.: 0 A
Max.: 3 A-
Page 1509 of 2000
BC–6BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEM
BC
SYSTEM DESCRIPTION
1. SYSTEM DESCRIPTION
HINT:
The skid control ECU forms a single unit with the ABS
and TRACTION actuator.
(a) ABS (Anti-lock Brake System):
The ABS helps prevent the wheels from locking
when the brakes are applied firmly or on a slippery
surface.
(1) Operation description:
The skid control ECU detects wheel lock
conditions by receiving vehicle speed signals
from each speed sensor, and sends control
signals to the pump motor and solenoid valve to
prevent wheels from locking by controlling the
brake fluid pressure of each wheel cylinder.
The ABS warning light comes on when the ABS
system malfunctions.
C115099E04
Page 1510 of 2000
BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEMBC–7
BC
(b) EBD (Electronic Brake Force Distribution):
The EBD control utilizes the ABS to create the
proper brake force distribution between the front
and rear wheels in accordance with the driving
conditions and vehicle load. In addition, when the
brakes are applied while cornering, it also controls
the braking forces of the right and left wheels,
helping to maintain vehicle stability.
(1) Operation description:
The skid control ECU receives speed signals
from each speed sensor to detect the slip
conditions of the wheels and sends control
signals to the solenoid.
The solenoid valve controls the brake fluid
pressure of each wheel cylinder and divides the
control power properly between the front and
rear wheels and the right and left wheels.
The brake warning light comes on to indicate
malfunctions in the EBD system.
C115100E05
Page 1511 of 2000
BC–8BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEM
BC
(c) BA (Brake Assist):
The primary purpose of the brake assist system is to
provide auxiliary brake force to assist drivers who
cannot generate a large enough brake force during
emergency braking, thus helping to maximize the
vehicle's braking performance.
(1) Operation description:
The skid control ECU receives speed signals
from each speed sensor and the fluid pressure
signal from the master cylinder pressure sensor
to determine whether brake assist is necessary.
If brake assist is deemed necessary, the skid
control ECU sends control signals to the pump
motor and solenoid. The pump and the solenoid
valve then control the pressure applied to each
wheel cylinder. The ABS warning light comes on
to indicate malfunctions in the BA (brake assist)
system.
w/ 16-inch disc: The brake warning light and
ABS warning light come on to indicate
malfunctions in the BA system.
C135908E01
Page 1513 of 2000
BC–10BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEM
BC
(1) Operation description:
The skid control ECU detects the vehicle's slip
condition by receiving signals from each speed
sensor and the ECM via CAN communication.
The skid control ECU controls engine torque
with the ECM via CAN communication and
brake fluid pressure through the pump and
solenoid valve. The slip indicator light blinks
when the system is operating.
for 4WD: The VSC warning light comes on when
the TRC system malfunctions.
for 2WD: The VSC warning light and SLIP
indicator light comes on when the TRC system
malfunctions.
Page 1515 of 2000

BC–12BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEM
BC
(1) Operation description:
The skid control ECU determines the vehicle
condition by receiving signals from the speed
sensor, the yaw rate and deceleration sensor
and the steering sensor. The skid control ECU
controls engine torque with the ECM via CAN
communication and brake fluid pressure through
the pump and solenoid valve. The slip indicator
light blinks and the skid control buzzer sounds
when the system is operating.
for 4WD: The VSC warning light comes on when
the TRC system malfunctions.
for 2WD: The VSC warning light and slip
indicator light come on when the TRC system
malfunctions.
(f) Downhill Assist Control:
When the downhill assist control switch is pressed
with the shift lever on L or R range and the
accelerator and brake pedals not depressed,
downhill assist control is activated. When activated,
4-wheel hydraulic pressure control occurs in order
to maintain a constant low vehicle speed without
causing the wheels to become locked. Thus, the
vehicle can descend a steep hill in a stable manner.
HINT:
• Depressing the accelerator and brake pedal
cancels control of the downhill assist control.
• Downhill assist control begins operating when
driving down on a slope at a speed of 25 km/h
(16 mph) or less with the engine brake applied.
Page 1516 of 2000
BRAKE CONTROL – VEHICLE STABILITY CONTROL SYSTEMBC–13
BC
(1) Operation description:
The slip indicator light blinks and the downhill
assist control indicator light and brake light come
on when the system is in operation.
The VSC warning light comes on and the
downhill assist control indicator light blinks to
indicate a malfunction in the downhill assist
control.
C136089E01
Page 1518 of 2000

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.