1996 TOYOTA RAV4 Service Repair Manual

BR3583
BR3582F00010
RotorSpeed Sensor
Magnet
To ECU
Low Speed High SpeedN S
+V
−V
− DIAGNOSTICSANTI−LOCK BRAKE SYSTEM
DI−257
1996 RAV4 (RM447U)
DTC 31, 32, 33, 34, 35 Speed Sensor Circuit
CIRCUIT DESCRIPTION
The speed sensor detects the wheel speed and sends the ap-
propriate signals to the ECU. These signals are used to control
the ABS system. The front and rear rotors each have 48 serra-
tions.
When the rotor rotate, the magnetic field emitted by the perma-
nent magnet in the speed sensor generates an AC voltage.
Since the frequency of this AC voltage changes in direct propor-
tion to the speed of the rotor, the frequency is used by the ECU
to detect the speed of each wheel.
DTC No.DTC Detecting ConditionTrouble Area
31, 32, 33, 34
Detection of any of conditions 1 through 3:
1. At vehicle speed of 10 km/h (6 mph) or more, pulses are not
input for 5 sec.
2. Momentary interruption of the speed sensor signal occurs
at least 7 times in the time between switching the ignition
switch ON and switching it OFF
3. Abnormal fluctuation of speed sensor signals with the ve-
hicle speed 20 km/h (12 mph) or more
Right front, left front, right rear or left rear speed sensor
Open or short in each speed sensor circuit
Sensor rotor
ECU
*35
Speed sensor signal is not input for about 1 sec. while the
speed sensor signals are being checked at vehicle speed of 0
km/hOpen in speed sensor circuit
ECU
*: 4WD models
HINT:
DTC No. 31 is for the right front speed sensor.
DTC No. 32 is for the left front speed sensor.
DTC No. 33 is for the right rear speed sensor.
DTC No. 34 is for the left rear speed sensor.
Fail safe function:
If trouble occurs in the speed sensor circuit, the ECU cuts off current to the ABS control (solenoid) relay and
prohibits ABS control.
DI98Z−01

W03168
*2*1
*1: 2WD models
*2: 4WD models*
2
*2
*2
*1
DI−258
− DIAGNOSTICSANTI−LOCK BRAKE SYSTEM
1996 RAV4 (RM447U)
WIRING DIAGRAM

R14676
21
R14669
1 2
− DIAGNOSTICSANTI−LOCK BRAKE SYSTEM
DI−259
1996 RAV4 (RM447U)
INSPECTION PROCEDURE
1 Check speed sensor.
Front
PREPARATION:
Disconnect the speed sensor connector.
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector.
OK:
Resistance: 0.6 − 1.8 kΩ
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector and body ground.
OK:
Resistance: 1 MΩ or higher
Rear:
PREPARATION:
Disconnect the speed sensor connector.
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector.
OK:
Resistance: 0.6 − 2.05 kΩ
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector and body ground.
OK:
Resistance: 1 MΩ or higher
NG Replace speed sensor.
NOTICE:
Check the speed sensor signal last (See page DI−234).
OK
2 Check for open and short in harness and connector between each speed sensor
and ECU (See page IN−30).
NG Repair or replace harness or connector.
OK

R03139
W01942
4WD Models
2WD Models
BR3795
OK
NG
DI−260
− DIAGNOSTICSANTI−LOCK BRAKE SYSTEM
1996 RAV4 (RM447U)
3 Check sensor rotor and sensor installation
Front:
PREPARATION:
Remove the brake disc (See page SA−20).
CHECK:
Check the sensor rotor serrations.
OK:
No scratches or missing teeth or foreign objects.
CHECK:
Check the sensor tip.
OK:
No scratches or foreign objects on the sensor tip.
CHECK:
Check the front speed sensor installation.
OK:
The installation bolt is tightened properly and there is
no clearance between the sensor and steering
knuckle.
Rear:
PREPARATION:
Remove the axle shaft (See page SA−52) or drive shaft (See
page SA−62).
CHECK:
Check the sensor rotor serrations.
OK:
No scratches or missing teeth or foreign objects.
CHECK:
Check the sensor tip.
OK:
No scratches or foreign objects on the sensor tip.
CHECK:
Check the speed sensor installation.
OK:
The installation bolt is tightened properly and there is
no clearance between the sensor and rear axle carri-
er.
NG Replace speed sensor or rotor.
NOTICE:
Check the speed sensor signal last (See page DI−234).
OK
Check and replace ABS ECU.

− DIAGNOSTICSANTI−LOCK BRAKE SYSTEM
DI−261
1996 RAV4 (RM447U)
DTC 37 Tires of Different Size (2WD Modules)
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
37Driving at more than 20 km/h (12 mph) for more than 20 sec.
with 1 or 2 tires of different size for 3 times continuouslyTire size
ECU
INSPECTION PROCEDURE
1 Check tire size.
NG Replace tires so that all 4 tires are of same size.
OK
Check and replace ABS ECU.
DI41N−02

W01939
W
1D
1K
21D
1F 74
4 2
9
1
6
W1E
1A
IB2 A16
A17
A1713 14
211 213
*
2*1
1 6 6 13 12 B−Y
B−YB−Y
GND
GND IG1
W−B
ALT F7
Fusible
Link
Block
BatteryJ/B No. 1
J/B No. 1ECU−IG IG Switch
J/B No. 1
ABS ECU
R/B No. 2
A17
A17 A17 2
W−B
EB
B−Y
*
1: 2WD models
*2: 4WD models B−Y
AM1
W DI−262
− DIAGNOSTICSANTI−LOCK BRAKE SYSTEM
1996 RAV4 (RM447U)
DTC 41 IG Power Source Circuit
CIRCUIT DESCRIPTION
This is the power source for the ECU, hence the CPU, and the actuators.
DTC No.DTC Detecting ConditionTrouble Area
41
Vehicle speed is 3 km/h (1.9 mph) or more and voltage of ECU
terminal IG1 remains at below 9.5 V for more than 10 sec.
4WD models:
Voltage of ECU terminal IG1 remains at more than 17 V for 1
sec. or moreBattery
IC regulator
Open or short in power source circuit
ECU
Fail safe function:
If trouble occurs in the power source circuit, the ECU cuts off current to the ABS control (solenoid) relay and
prohibits ABS control.
WIRING DIAGRAM
DI41O−02

BE6653
W01408
R15782
F15317
ON
2WD Models
IG1
GNDGND
GND (−) (+)
IG1
4WD Models
(−)(+)
GND
− DIAGNOSTICSANTI−LOCK BRAKE SYSTEM
DI−263
1996 RAV4 (RM447U)
INSPECTION PROCEDURE
1 Check battery positive voltage.
OK:
Voltage: 10 − 14 V
NG Check and repair charging system.
OK
2 Check voltage between terminals IG1 and GND of ABS ECU connector.
PREPARATION:
Remove the ABS ECU with connectors still connected.
CHECK:
(a) Turn the ignition switch ON.
(b) Measure the voltage between terminals IG1 and GND of
the ABS ECU connector.
OK:
Voltage: 10 − 14 V
OK Check and replace ABS ECU.
NG

BE6053
W01409
R15783
F15318
LOCK
2WD Models
GND 4WD Models
GNDGND GND
DI−264
− DIAGNOSTICSANTI−LOCK BRAKE SYSTEM
1996 RAV4 (RM447U)
3 Check continuity between terminals GND of ABS ECU connector and body
ground.
CHECK:
Measure the resistance between terminals GND of the ABS
ECU connector and body ground.
OK:
Resistance: 1 Ω or less
NG Repair or replace harness or connector.
OK