TOYOTA LAND CRUISER 1998 Factory Repair Manual

F12707
GL1GL2
VYSGYAW
Front
Rearward
Forward
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-569
762 Author
: Date
:
2004 LAND CRUISER (RM1071U)
2 Check yaw rate (deceleration) sensor.
PREPARATION:
(a) Connect 3 dry batteries of 1.5 V in series.
(b) Connect VYS terminal to the batteries' positive (+) termi-
nal, and GYAW terminal to the batteries' negative (-) ter-
minal. Apply about 4.5 V between VYS and GYAW termi-
nals.
NOTICE:
Do not apply voltage of 6 V or more to terminals VYS and
GYAW.
CHECK:
Check the output voltage of GL1 and GL2 terminals when the
sensor is tilted forward and rearward.
OK:
SymbolsConditionStandard Value
GL1HorizontalAbout 2.3 V
GL1Lean rearward1.0 V to about 2.3 V
GL1Lean forwardAbout 2.3 V to 3.5 V
GL2HorizontalAbout 2.3 V
GL2Lean rearwardAbout 2.3 V to 3.5 V
GL2Lean forward1.0 V to about 2.3 V
HINT:

If the sensor is tilted too much, it may show the wrong val-
ue.

If dropped, the sensor should be replaced with a new one.

The sensor removed from the vehicle should not be
placed upside down.
NG Replace yaw rate sensor.
OK
Check and replace skid control ECU.

F02870
Master Cylinder
Pressure Sensor
(Shielded)ABS & BA & TRAC
& VSC ECU
MSS VCM
E2 22
VOUT10
3 21
23 VCC
PMC
GND M4
A41 B
WR
A4112 A41
A41 DI-570
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
763 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC C1246 / 46 Master Cylinder Pressure Sensor
Circuit
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1246 / 46
Either of the following 1., 2., 3., 4. or 5. is detected:
1. At a vehicle speed of 4 mph (7 km/h) or more, PMC ter-
minal voltage does not change by more than 0.005 V
once it exceeds 0.86 V continues for at least 30 secs.
2. Interference occurs to ECU terminal PMC 7 times or
more for 5 sec.
3. ECU terminal STP is OFF, and the condition that termi-
nal PMC voltage becomes more than 0.86 V or less than
0.3 V continues for 5 sec. or more.
4. The condition that ECU terminal IG1 voltage is 9.5 V to
17.0 V, and terminal VCM voltage other than the range
from 4.4 V to 5.6 V continues for 1.2 sec. or more.
5. The condition that ECU terminal VCM voltage is 4.4 V to
5.6 V, and terminal PMC voltage other than the range
from 0.14 V to 4.85 V continues for 1.2 sec. or more.

Master cylinder pressure sensor

Master cylinder pressure sensor circuit
WIRING DIAGRAM
DIC9R-01

- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-571
764 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 2 in case of not
using the hand-held tester.
1 Check output value of the master cylinder pressure sensor.
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:
Check that the brake fluid pressure value of the master cylinder pressure sensor displayed on the hand-held
tester is changing when depressing the brake pedal.
OK:
Brake fluid pressure value must be changing.
OK Go to step 4.
NG
2 Check master cylinder pressure sensor.
PREPARATION:
(a) Install the LSPV gauge to the front caliper bleeder plug portion, and bleed the LSPV gauge.
SST 09709-29018
(b) Remove the air cleaner inlet and battery clamp cover.
CHECK:
Start the engine and depress the brake pedal, then check the relation between the fluid pressure and voltage
of PMC and E2 terminals of the skid control ECU with connectors still connected.
OK:
Front brake caliper fluid pressureVoltage
0 kPa (0 Kgf/cm2, 0 psi)0.37 to 0.63 V
5,883 kPa (60 kgf/cm2, 853 psi)1.57 to 1.83 V
11,768 kPa (120 kgf/cm2, 1,706 psi)2.77 to 3.03 V
HINT:
Voltage between terminals VCM and E2: 4.7 to 5.3 V
NG Replace master cylinder pressure sensor.
OK

DI-572- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
765 Author
: Date
:
2004 LAND CRUISER (RM1071U)
3 Check for open and short circuit in harness and connector between master cyl-
inder pressure sensor and skid control ECU (See page IN-36).
NG Repair or replace harness or connector.
OK
Replace master cylinder pressure sensor.
4 Check whether or not the ECU terminal STP input voltage is changed when the
stop light switch is turned on and off.
NO Check the stop light switch circuit (See page
DI-573).
YES
Check and replace skid control ECU.

- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-573
766 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC C1249 / 49 Stop Light Switch Circuit
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1249 / 49
ECU terminal IG1 voltage is 9.5 to 17.2 V, ABS is in non-
operation, and an open in stop light switch circuit continues
for 0.3 sec. or more.
Stop light bulb

Stop light switch circuit
DIC9S-02

F17777F18531
ABS & BA & TRAC
& VSC ECU
S5
Stop Light SW
F16
Fl Block
H11
High Mounted
Stop Light STOP
R12
Rear Combination
Light RHSTP A4210
G-W
2B 23
2K 35
2D 35
2D31
2C
B-G1
ALT
J/B No.21 G-W
21
G-R
BP38
G-W
BH22
G-W
21W-B
BH2 5
W-B
BP3
6 3 5 G-W
G-W
BQ23
G-W G-W
31W-B
W-B
BQ2 10
G-W
31
W-B
BJ BM
BJ BK 3 5 BL48
G-W
BD27 G-W
W-B
W-B
W-B
W-BW-B
W-B G-W
BatteryR13
Rear Combination
Light RHR10
Rear Combination
Light LH
R11
Rear Combination Light LH
G-WCowl Side J/B LH
G-WG-W
W-B
3BH2
(*2)
(*1)
*1: w/ Navigation System
*2: w/o Navigation System DI-574
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
767 Author
: Date
:
2004 LAND CRUISER (RM1071U)
WIRING DIAGRAM

F08298
STP
(-) (+)
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-575
768 Author
: Date
:
2004 LAND CRUISER (RM1071U)
INSPECTION PROCEDURE
1 Check operation of the stop light switch.
CHECK:
Check that the stop light lights up when the brake pedal is depressed and goes OFF when the brake pedal
is released.
OK Go to step 3.
NG
2 Check stop light circuit (See page BE-50).
NG Check stop light bulb and repair or replace stop
light circuit.
OK
3 Check voltage between terminal STP of skid control ECU and body ground.
PREPARATION:
Remove the skid control ECU with connectors still connected.
CHECK:
Measure voltage between terminal STP of the skid control ECU
and body ground when the brake pedal is depressed.
OK:
Voltage: 10 to 14 V
OK Proceed to next circuit inspection shown in
problem symptoms table (See page IN-36).
NG

DI-576- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
769 Author
: Date
:
2004 LAND CRUISER (RM1071U)
4 Check for open circuit in harness and connector between skid control ECU and
stop light switch (See page IN-36).
NG Repair or replace harness or connector.
OK
Check and replace skid control ECU.

F17712
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
21ABS & BA & TRAC
& VSC ECU
- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEMDI-577
770 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC C1251 / 51 Hydraulic Brake Booster Pump Motor
Malfunction
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1251 / 51
Either of the following 1. or 2. is detected:
1. After turning the ignition switch ON, the current of more
than 30 A flows to the motor for more than 1 sec.
2. After turning the ignition switch ON, less than 7 A
change in current is detected more than 3 times in a row
when the motor is ON.
Hydraulic brake booster pump motor
WIRING DIAGRAM
DIC9T-02

F02859
(-)
(+)
(-)
(+)
BM2
BM1EM1 EM2
F04505
BM1
EM1MT
MT+
MT-
BM2
EM2
DI-578- DIAGNOSTICSABS & VEHICLE STABILITY CONTROL (VSC) &
BRAKE ASSIST (BA) SYSTEM
771 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 4.
OK
2 Check hydraulic brake booster resistance.
PREPARATION:
Disconnect the 2 connectors from the hydraulic brake booster.
CHECK:
Check resistance between terminals MT+ and MT-, BM1 and
MT, BM2 and MT, EM1 and MT+, EM2 and MT+ of the hydraulic
brake booster connector.
OK:
30 to 36 W
NG Replace the hydraulic brake booster assembly.
OK