Page 833 of 3115
F02859
(-)
(+)
(-)
(+)
BM2
BM1EM1 EM2
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-581
774 Author: Date:
2004 LAND CRUISER (RM1071U)
INSPECTION PROCEDURE
1 Check operation of hydraulic brake booster pump motor.
PREPARATION:
Disconnect the 2 connectors from the hydraulic brake booster.
CHECK:
Connect the battery positive lead to terminal BM1 or BM2
and the battery negative lead to terminal EM1 or EM2 of the
hydraulic brake booster (pump motor) connector.
OK:
The operation sound of the pump motor should be
heard.
NG Go to step 9.
OK
2 Check for short circuit (to B+) in harness and connector between BM1 or BM2 of
hydraulic brake booster and ABS motor 1 relay or ABS motor 2 relay
(See page IN-36).
NG Repair or replace harness or connector.
OK
3 Check for short circuit (to B+) in harness and connector between MT of hydrau-
lic brake booster and skid control ECU (See page IN-36).
NG Repair or replace harness or connector.
OK
Page 834 of 3115

F02861
LOCKON
PH
PHG
DI-582- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
775 Author: Date:
2004 LAND CRUISER (RM1071U)
4 Check pressure switch (PH).
In case of using the hand-held tester:
PREPARATION:
(a) Connect the hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand-held tester main switch ON.
(c) Select the DATA LIST mode on the hand-held tester.
CHECK:
Depress the brake pedal more than 40 times with the ignition switch OFF, then turn the ignition switch ON
and check the pressure switch (PH) condition.
HINT:
When pressure in the power supply system is released, reaction force becomes light and stroke becomes
longer.
OK:
ºOFFº turns to ºONº.
HINT:
OFF: Low pressure
ON: High pressure
In case of not using the hand-held tester:
PREPARATION:
(a) Disconnect the connector (5P) from the hydraulic brake
booster.
(b)
With the ignition switch OFF, depress the brake pedal more than
40 times to decrease the accumulator pressure.
HINT:
When pressure in the power supply system is released, reac-
tion force becomes light and stroke becomes longer.
CHECK:
Measure resistance between terminals PH and PHG of the hy-
draulic brake booster connector.
OK:
Resistance: 1.0 kW
PREPARATION:
(a) Connect the connector (5P) to the hydraulic brake boost-
er.
(b) Disconnect the connector (5P) after the ignition switch is
turned ON and the pump motor is stopped.
CHECK:
Measure resistance between terminals PH and PHG of the hy-
draulic brake booster connector.
OK:
Resistance: 0 W
HINT:
After inspection, connect the connector and clear the DTC (See
page DI-505).
NG Replace hydraulic brake booster assembly.
Page 835 of 3115

F02863
LOCK
ONPL
PLG
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-583
776 Author: Date:
2004 LAND CRUISER (RM1071U)
OK
5 Check pressure switch (PL).
In case of using hand-held tester:
PREPARATION:
(a) Connect the hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand-held tester main switch ON.
(c) Select the DATA LIST mode on the hand-held tester.
CHECK:
Depress the brake pedal more than 40 times with the ignition switch OFF, then turn the ignition switch ON
and check the pressure switch (PL) condition.
HINT:
When pressure in the power supply system is released, reaction force becomes light and stroke becomes
longer.
OK:
ºOFFº turns to ºONº.
HINT:
OFF: Low pressure
ON: High pressure
In case of not using hand-held tester:
PREPARATION:
(a) Disconnect the connector (8P) from the hydraulic brake
booster.
(b) With the ignition switch OFF, depress the brake pedal
more than 40 times to decrease the accumulator pres-
sure.
HINT:
When pressure in the power supply system is released, reac-
tion force becomes light and stroke becomes longer.
CHECK:
Measure resistance between terminals PL and PLG of the hy-
draulic brake booster connector.
OK:
Resistance: 5.7 kW
PREPARATION:
(a) Connect the connector (8P) to the hydraulic brake boost-
er.
(b) Disconnect the connector (8P) after the ignition switch is
turned ON and the pump motor is stopped.
CHECK:
Measure resistance between terminals PL and PLG of the hy-
draulic brake booster connector.
OK:
Resistance: 1.0 kW
Page 836 of 3115

F00044
1
2
3 4
(+) (-) Continuity1 2
3 4
1
2
3 4 Open
Continuity DI-584
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
777 Author: Date:
2004 LAND CRUISER (RM1071U)
HINT:
After inspection, connect the connector and clear the DTC (See
page DI-505).
NG Replace hydraulic brake booster assembly.
OK
6 Check for short circuit (to B+) in harness and connector between pressure
switch and skid control ECU (See page IN-36).
NG Repair or replace harness or connector.
OK
7 Check ABS motor 1 relay and ABS motor 2 relay.
PREPARATION:
Remove the ABS motor 1 relay and ABS motor 2 relay from the
engine room J/B.
CHECK:
Check continuity between the motor relay terminals listed in the
table below.
OK:
Terminals 3 and 4Continuity
(Reference value *1)
Terminals 1 and 2Open
*1: ABS motor 1 relay: 54 W
ABS motor 2 relay: 62 W
CHECK:
(a) Apply battery positive voltage between terminals 3 and 4.
(b) Check continuity between terminals.
OK:
Terminals 1 and 2Continuity
Page 837 of 3115
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-585
778 Author: Date:
2004 LAND CRUISER (RM1071U)
NG Replace ABS motor 1 relay or ABS motor 2
relay.
OK
8 Check for short circuit in harness and connector between ABS motor 1 relay or
ABS motor 2 relay and skid control ECU (See page IN-36).
NG Repair or replace harness or connector.
OK
Check and replace skid control ECU.
9 Check for open or short circuit in harness and connector between hydraulic
brake booster and skid control ECU (See page IN-36).
NG Replace wire harness.
OK
10 Check hydraulic brake booster pump motor (See page BR-64).
NG Replace hydraulic brake booster pump motor.
OK
Replace
hydraulic brake booster.
Page 838 of 3115

DI-586- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
779 Author: Date:
2004 LAND CRUISER (RM1071U)
DTC C1253 / 53 Motor Relay Circuit
CIRCUIT DESCRIPTION
The ABS motor 1 relay and ABS motor 2 relay supply power to the hydraulic brake booster pump motor.
While the ABS & BA & TRAC & VSC are activated, the ECU switches the motor relay ON and operates the
hydraulic brake booster pump motor.
DTC No.DTC Detecting ConditionTrouble Area
C1253 / 53
When any of the following 1. through 4. is detected:
1. After turning the ignition switch ON, open in the relay
coil is detected for more than 1 sec.
2. When the pressure switch does not control motor
driving, the condition that the motor relay is always ON
continues for more than 1 sec. due to short circuit.
3. When the pressure switch (PH) detects the low
pressure or while the pump motor operates to increase
the pressure, the condition that the motor relay does not
turn ON continues for more than 0.2 sec.
4. When pressure switch does not control motor driving,
the condition that the motor relay is always ON due to
the welded contact continues for more than 2 sec.
ABS motor 1 or ABS motor 2 relay
ABS motor 1 or ABS motor 2 relay circuit
Hydraulic brake booster pump motor circuit
DIC9V-02
Page 839 of 3115
F17712
ABS & BA & TRAC
& VSC ECU ABS & BA & TRAC
& VSC Actuator
Engine Room R/B
FL Block
Cowl Side J/B LH
Battery ABS MTR2 Relay
ABS MTR1 RelayMTT A4127
MT+ A4128
MT- A4118
MR2
A442
R2+
A443
W-L
1
1C 1
1 1
2ABS No.2
3 41
2 1
1
1
1B-R
L
GR
Y-B A387
A385
A388
A383
L-R
R
A372
A371
A386
A401
W-BW-BW-B
W-B W-B
EE2A3
IF
GND GND2GND1BM1 BM2 MT- MT+MTT
B-GF152
MAIN
P
R
A41MR1 29 A41
R1+ 1
W-B 43
21
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-587
780 Author: Date:
2004 LAND CRUISER (RM1071U)
WIRING DIAGRAM
Page 840 of 3115
DI-588- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
781 Author: Date:
2004 LAND CRUISER (RM1071U)
INSPECTION PROCEDURE
HINT:
Start the inspection from step 1, in case of using the hand-held tester and start from step 3, in case of not
using hand-held tester.
1 Check ABS motor 1 and ABS motor 2 relay operation.
PREPARATION:
(a) Connect the hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand-held tester main switch ON.
(c) Select the ACTIVE TEST mode on the hand-held tester.
CHECK:
Check the operation sound of the ABS motor relays individually when operating it with the hand-held tester.
OK:
The operation sound of the ABS motor 1 relay and ABS motor 2 relay should be heard.
NG Go to step 3.
OK
2 Check for short circuit (to B+) in harness and connector between MT of hydrau-
lic brake booster and skid control ECU (See page IN-36).
NG Repair or replace harness or connector.
OK
Check and replace skid control ECU.