142
ABS
THIS SYSTEM CONTROLS THE RESPECTIVE BRAKE FLUID PRESSURES ACTING ON THE DISC BRAKE CYLINDERS OF THE RIGHT
FRONT WHEEL, LEFT FRONT WHEEL AND REAR WHEELS WHEN THE BRAKES ARE APPLIED IN A PANIC STOP SO THAT THE
WHEELS DO NOT LOCK. THIS RESULTS IN IMPROVED DIRECTIONAL STABILITY AND STEERABILITY DURING PANIC BRAKING.
1. INPUT SIGNALS
(1) SPEED SENSOR SIGNAL
THE SPEED OF THE WHEELS IS DETECTED AND INPUT TO TERMINALS FL+, FR+, RL+ AND RR+ OF THE ABS ECU.
(2) STOP LIGHT SW SIGNAL
A SIGNAL IS INPUT TO TERMINAL STP OF THE ABS ECU WHEN BRAKE PEDAL IS OPERATED.
(3) PARKING BRAKE SW SIGNAL (4 WD)
A SIGNAL IS INPUT TO TERMINAL PKB OF THE ABS ECU WHEN THE PARKING BRAKE IS OPERATED.
(4) DECELERATION SENSOR SIGNAL (4 WD)
LONGITUDINAL ACCELERATION IS DETECTED AND A SIGNAL IS INPUT TO THE ABS ECU.
2. SYSTEM OPERATION
DURING SUDDEN BRAKING THE ABS ECU, WHICH HAS SIGNALS INPUT FROM EACH SENSOR, CONTROLS THE CURRENT FLOWING
TO THE SOLENOID INSIDE THE ACTUATOR AND LETS THE HYDRAULIC PRESSURE ACTING ON EACH WHEEL CYLINDER ESCAPE TO
THE RESERVOIR. THE PUMP INSIDE THE ACTUATOR IS ALSO OPERATING AT THIS TIME AND IT RETURNS THE BRAKE FLUID FROM
THE RESERVOIR TO THE MASTER CYLINDER, THUS PREVENTING LOCKING OF THE VEHICLE WHEELS.
IF THE ECU JUDGES THAT THE HYDRAULIC PRESSURE ACTING ON THE WHEEL CYLINDER IS INSUFFICIENT, THE CURRENT
ACTING ON THE SOLENOID IS CONTROLLED AND THE HYDRAULIC PRESSURE IS INCREASED. HOLDING OF THE HYDRAULIC
PRESSURE IS ALSO CONTROLLED BY THE ECU, BY THE SAME METHOD AS ABOVE. BY REPEATED PRESSURE. REDUCTION,
HOLDING AND INCREASE ARE REPEATED TO MAINTAIN VEHICLE STABILITY AND TO IMPROVE STEERABILITY DURING SUDDEN
BRAKING.
A 8 (A), A 9 (B) ABS RELAY
(A) 1, (B) 2-GROUND : ALWAYS APPROX. 12 VOLTS
(B) 6-GROUND : ALWAYS CONTINUITY
A10, A11 ABS SPEED SENSOR FRONT LH, RH
1-2 : APPROX. 0.92-1.22 KW (20C, 68F)
A12, A13 ABS SPEED SENSOR REAR LH, RH
1-2 : APPROX. 0.92-1.22 KW (20C, 68F)
A16 (A), (C), A17 (B), (D) ABS ECU
(CONNECT THE ECU CONNECTORS)
(A) 8, (D) 6-GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION AND
DATA LINK CONNECTOR 1 TS-E1 NOT CONNECTED
(A) 9, (D) 20-GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION AND
DATA LINK CONNECTOR 1 TC-E1 NOT CONNECTED
(B) 4, (C) 1- GROUND,(B) 1,(C) 2-GROUND :
(B) 5, (C) 9-GROUND,(B) 12,(C) 10-GROUND :
(B) 11, (D) 12-GROUND,(B) 10,(D) 13-GROUND :
(B) 22, (D) 25-GROUND,(B) 21,(D) 26-GROUND :
(B) 2,(D) 11-GROUND :
(B) 13,(D) 24-GROUND :
(A) 2, (D) 10-GROUND : APPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
(A) 12, (D) 21-GROUND : APPROX. 12 VOLTS WITH BRAKE PEDAL DEPRESSED
(D) 22-GROUND : ALWAYS APPROX. 12 VOLTS
A21, A22 ABS SPEED SENSOR REAR LH, RH
1-2 : APPROX. 0.8-1.2 KW (20C, 68F)
P 2 PARKING BRAKE SW
1-GROUND : CLOSED WITH PARKING BRAKE LEVER PULLED UP
S 5 STOP LIGHT SW
2-1 : CLOSED WITH BRAKE PEDAL DEPRESSED
ALWAYS CONTINUITYAPPROX. 12 VOLTS WITH IGNITION SW AT ON POSITION
AND ABS WARNING LIGHT GOES OFF
SYSTEM OUTLINE
SERVICE HINTS
SA1YC−02
F03505
R10700
SA−52
− SUSPENSION AND AXLEREAR AXLE HUB (2WD)
1996 RAV4 (RM447U)
REMOVAL
1. REMOVE REAR WHEEL
Torque: 103 N·m (1,050 kgf·cm, 76 ft·lbf)
2. REMOVE BRAKE DRUM
3. CHECK BEARING BACKLASH AND AXLE HUB DEVI-
ATION
(a) Using a dial indicator near the center of the axle hub and
check the backlash in bearing shaft direction.
Maximum: 0.05 mm (0.0020 in.)
If the backlash exceeds the maximum, replace the axle hub with
bearing.
(b) Using a dial indicator, check the deviation at the surface
of the axle hub outside the hub bolt.
Maximum: 0.07 mm (0.0028 in.)
If the deviation exceeds the maximum, replace the axle hub
with bearing.
4. w/ ABS:
DISCONNECT ABS SPEED SENSOR
Torque: 8 N·m (80 kgf·cm, 69 in.·lbf)
5. w/ ABS:
REMOVE AXLE SHAFT
(a) Remove the cotter pin and lock cap.
(b) With applying the brakes, remove the nut.
(c) Remove the axle shaft.
Torque: 206 N·m (2,100 kgf·cm, 152 ft·lbf)
6. DISASSEMBLE REAR BRAKE (See page BR−30)
7. DISCONNECT BRAKE LINE
Using SST, disconnect the brake line from the wheel cylinder.
SST 09023−00100
Torque: 15 N·m (155 kgf·cm, 11 ft·lbf)
R10041
SST
SA0UC−03
R10773Matchmarks SA−62
− SUSPENSION AND AXLEREAR DRIVE SHAFT
1996 RAV4 (RM447U)
REMOVAL
NOTICE:
The hub bearing could be damaged if it is subjected
to the vehicle weight, such as when moving the ve-
hicle with the drive shaft bearing removed. Therefore,
if it is absolutely necessary to place the vehicle
weight on the hub bearing, first support it with SST.
SST 09608−16042 (09608−02021, 09608−02041)
w/ ABS:
After disconnecting the drive shaft from the axle hub,
work carefully so as not to damage the sensor rotor
serrations on the drive shaft.
1. REMOVE REAR WHEEL
Torque: 103 N·m (1,050 kgf·cm, 76 ft·lbf)
2. w/ ABS:
REMOVE BOLT AND ABS SPEED SENSOR
Torque: 7.8 N·m (80 kgf·cm, 69 ft·lbf)
3. REMOVE DRIVE SHAFT LOCK NUT
(a) Remove the cotter pin and lock cap.
(b) With depressing the brakes, remove the nut.
Torque: 206 N·m (2,100 kgf·cm, 152 ft·lbf)
4. REMOVE DRIVE SHAFT
(a) Place matchmarks on the drive shaft and differential side
gear shaft.
(b) Remove the 4 nuts and washers, and disconnect the
drive shaft from the differential side gear shaft.
Torque: 56 N·m (570 kgf·cm, 41 ft·lbf)
(c) Remove the drive shaft from the axle carrier.
