1996 TOYOTA LAND CRUISER brake system

DI5LZ−03
DI−200
−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
1996 LAND CRUISER (RM451U)
PROBLEM SYMPTOMS TABLE
If a normal code is displayed during the DTC check but the problem still o\
ccurs, check the circuits for each
problem symptom in the order given in the table below and proceed to the releva\
nt troubleshooting page.
SymptomsSuspected AreaSee page
ABS does not operate
Only when 1 − 4 are all normal and the problem is still occurring, replace the ABS
ECU
2. Check the DTC reconfirming that the normal code is output
3. IG power source circuit
4. Speed sensor circuit
5. Check the ABS actuator with a checker
If abnormal, check the hydraulic circuit for leakage (See page DI−237)
DI−190
DI−215
DI−210
BR−53
ABS does not operate effi-
ciently
Only when 1 − 4 are all normal and the problem is still occurring, replace the ABS
ECU
1. Check the DTC reconfirming that the normal code is output
2. Speed sensor circuit
3. Stop light switch circuit
4. Check the ABS actuator with a checker
If abnormal, check the hydraulic circuit for leakage (See page DI−237)
DI−190
DI−210
DI−228
BR−53
ABS warning light abnormal1. ABS warning light circuit
2. ABS ECUDI−230 −
DTC check cannot be done
Only when 1 and 2 are all normal and the problem is still occurring, rep\
lace the
ABS ECU
1. ABS warning light circuit
2. Tc terminal circuit
DI−230
DI−233
Speed sensor signal check
cannot be done1. Ts terminal circuit
2. ABS ECUDI−235−
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010

DI5M0−02
W02192
22 1
4
ABS
R/B
No. 2
W
B−R
W−B
ID
1 1
1
2
2
2
3
64
4 3
6
3
511
18
G
G−B
G−Y
DLC1 ABS ECU
MR
R−
SR
AST MT
L−Y
L−W
ABS Actuator ABS Control Relay
Motor
Relay
Solenoid
Relay
ABS ECU
A6A4
A13A5
F6
Battery
B−L
2
2
12 B−W
B−W
B−W
EA312
5
A5
A4
A4 A6
A6
A6
A7
A7
A7 A7A13 A13
A13 A13
24
23
B−L
EA312 V 12 V
B−W
AM1
W−B W−B
R/B
No. 2 B−W
−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
DI−201
1996 LAND CRUISER (RM451U)
CIRCUIT INSPECTION
DTC 11, 12 ABS Control (Solenoid) Relay Circuit
CIRCUIT DESCRIPTION
This relay supplies power to each ABS solenoid. After the ignition switch is\
turned ON, if the initial check is
OK, the relay goes on.
DTC No.DTC Detecting ConditionTrouble Area
11
Conditions (1) and (2) continue for 0.2 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage: Battery positive voltage
2. (2) ABS control (solenoid) relay monitor terminal (AST) voltage: 0 V
ABS control (solenoid) relay
 Open or short in ABS control (solenoid) relay circuit
12
Conditions 1 and 2 continue for 0.2 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage:
0 V
2. ABS control (solenoid) relay monitor terminal (AST) volt- age: Battery positive voltage
ABS control (solenoid) relay
 B+ short in ABS control (solenoid) relay circuit
Fail safe function:
If trouble in the ABS control (solenoid) relay circuit, the ECU cuts off current to the ABS control (solenoid)
relay and prohibits ABS control.
WIRING DIAGRAM
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010

BE6653R14203 F00001
LOCK
2
6 A7
(+)
(−)
R00888
5
4
2
18
ABS Control
Relay
ABS
Actuator
ABS ECU A7
A4
A5 A5
A4
A13
DI−202
−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
1996 LAND CRUISER (RM451U)
INSPECTION PROCEDURE
1 Check voltage between terminals A7−2 and A7−6 of ABS control relay connector.
PREPARATION:
Disconnect the ABS control relay connector.
CHECK:
Measure the voltage between terminals A7 −2 and A7−6 of the
ABS control relay harness side connector.
OK:
Voltage: 10 − 14 V
NG Check and repair harness or connector.
OK
2 Check continuity between terminals A7−5 and A4−4, A4−4 and A5−2, and A5−2 and A13−18.
PREPARATION:
Disconnect the 2 connectors from the ABS actuator.
CHECK:
Check the continuity between terminals A7 −5 and A4−4, A4 −4
and A5−2, and A5−2 and A13−18.
OK:
Continuity
HINT:
There is a resistance of 4 ∼ 6 Ω between terminals A4 −4 and
A5−2.
NG Repair or replace harness or ABS actuator.
OK
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010

R14139
ContinuityOpen
Continuity
1
2
5
6
3
A6
A7
R14140
(−) (+)
Continuity
Open
36
51
2
A6 A7
−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
DI−203
1996 LAND CRUISER (RM451U)
3 Check ABS control (solenoid) relay.
CHECK:
Check the continuity between each terminal of the ABS control
(solenoid) relay.
OK:
Terminals A7 −1 and A6− 3Continuity
(Reference value aprox. 80 Ω)
Terminals A7 −5 and A7− 6Continuity
Terminals A7 −2 and A7− 5Open
CHECK:
(a) Apply battery positive voltage between terminals A7 −1
and A6−3.
(b) Check the continuity between each terminal of the ABS control (solenoid) relay.
OK:
Terminals A7 −5 and A7− 6Open
Terminals A7 −2 and A7− 5Continuity
NG Replace ABS control relay.
OK
4 Check for open and short in harness and connector between ABS control (\
sole- noid) relay and ABS ECU (See page IN−28).
NG Repair or replace harness or connector.
OK
If same code is still output after DTC is deleted, check contact condition of each connection.\
If
connections are normal, ECU may be defective.
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010

−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
DI−207
1996 LAND CRUISER (RM451U)
DTC 21, 22, 23 ABS Actuator Solenoid Circuit
CIRCUIT DESCRIPTION
This solenoid goes on when signals are received from the ECU and controls the pressure acting on the wheel
cylinders thus controlling the braking force.
DTC No.DTC Detecting ConditionTrouble Area
21
Conditions 1 through 3 continue for 0.05 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage:
Battery positive voltage
2. Voltage of ABS ECU terminal AST: Battery positive voltage
3. When power transistor of ECU is ON, voltage of terminal SFR is 0 V or battery positive voltage
ABS actuator
 Open or short in SFR circuit
22
Conditions 1 through 3 continue for 0.05 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage:
Battery positive voltage
2. Voltage of ABS ECU terminal AST: Battery positive volt- age
3. When power transistor of ECU is ON, voltage of terminal SFL is 0 V or battery positive voltage
ABS actuator
 Open or short in SFL circuit
23
Conditions 1 through 3 continue for 0.05 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage:
Battery positive voltage
2. Voltage of ABS ECU terminal AST: Battery positive voltage
3. When power transistor of ECU is ON, voltage of terminal SRR is 0 V or battery positive voltage
ABS actuator
 Open or short in SRR circuit
Fail safe function:
If trouble occurs in the actuator solenoid circuit, the ECU cuts off current to the ABS control (solenoid) relay
and prohibits ABS control.
DI5M2−02
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010

W02193
2
2 1
3
ABS
Battery
W
B−W
W−BID
1
W−B 1
1
W−B 2
2
3 5
4
6
3
4
DLC1
ABS Actuator ABS Control Relay
Motor
Relay
Solenoid
Relay
ABS ECULG
L−R ABS ECU
ABS ECU
3
4
1
1
13
26
SFR
SFL
SRR
A6
A4 A5
A13
A7A6
A6 A6
A4 A4
A5
A5
A13
A13
F6
EA3
L
B−W
B−W
2
2
2
2
EA31
A7 A7
A7
B−RBL
4
1
B−L
AM1
Monitor
R/B
No. 2
B−W
B−W
R/B
No. 2
F00026
1
3
LOCK
7
4
A5
A4
4
DI−208
−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
1996 LAND CRUISER (RM451U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check ABS actuator solenoid.
PREPARATION:
Disconnect the 2 connectors from the ABS actuator.
CHECK:
Check the continuity between terminals A4 − 4 and A5−1, 3, 4
of the ABS actuator connector.
OK:
Continuity
HINT:
Resistance of each solenoid coil is 0.8 − 1.6 Ω
NG Replace ABS actuator.
OK
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010

−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
DI−209
1996 LAND CRUISER (RM451U)
2 Check for open and short in harness and connector between ABS ECU and ac-
tuator (See page IN−28 ).
NG Repair or replace harness or connector.
OK
If same code is still output after DTC is deleted, check contact condition of each connection.\
If
connector are normal, ECU may be defective.
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010

BR3583
BR3582F00010
RotorSpeed Sensor
Magnet
To ECU
+V
-V High Speed
Low Speed
Coil
N
S
-
DIAGNOSTICS ANTI-LOCK BRAKE SYSTEM
DI-210
1996 LAND CRUISER (RM451U)
DTC31, 32, 33, 34, 35, 36 Speed Sensor Circuit
CIRCUIT DESCRIPTION
The speed sensor detects 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 rotors 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 oc-
curs at least 7 times in the time between switching the igni-
tion switch ON and switching it OFF.
(3) Abnormal fluctuation of speed sensor signals with the
vehicle speed 20 km/h (12 mph) or more.

Right front, left front, right rear and left rear speed sensor

Open or short in each speed sensor circuit

Sensor rotor
35
Speed sensor signal is not input for about 1 sec. while
the left front and right rear speed sensor signals are being
checked with the IG switch ON.

Open in left front or right rear speed sensor circuit
36
Speed sensor signal is not input for about 1 sec. while
the right front and left rear speed sensor signals are being
checked with the IG switch ON.

Open in right front or left rear speed sensor circuit
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.
DI5M3-02
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010