2000 LEXUS GS400 sensor

I04251

Combination Meter Wiring Circuit ± 2
Left Turn Indicator
Right Turn Indicator
Hi±beam Indicator
SRS Warning
Washer Level Indicator
Headlight leveling
Indicator
Malfunction
Indicator
VSC Warning
ABS Warning
VSC OFF Indicator
SLIP Indicator IG+IG+ IG+
IG+
IG+
IG+Combination Meter ECU
A14 A15 A16 A13 A12 B18 A10 to HEAD FuseB15B3B2
A7
B12Headlight Dimmer Switch
Airbag Sensor Assembly
Washer Fluid Level
Warning Switch
Healight Leveing
Contorl ECU
ECM
ABS, TRAC and
VSC ECU Turn Singal
Flasher RelayODO/TRIP Switch
RESET Switch to Combination Meter ECU
to Combination Meter ECUU8
U3
U10
U9
U4
SRS +B BE±84
± BODY ELECTRICALCOMBINATION METER
2385 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

Clock (Passenger seat belt warning light)
Tilt and telescopic ECU
Fuel main sender gauge
Fuel sub sender gauge
ABS, TRAC and VSC ECU (Speed signal)
Speed control unit
Headlight dimmer switch
Ground
Window washer level warning switch
Body control No.2 ECU
ECM
ABS, TRAC and VSC ECU (VSC warning light)
ABS, TRAC and VSC ECU (SLIP warning light)
ABS, TRAC and VSC ECU (TRAC OFF warning light)
ABS, TRAC and VSC ECU (ABS warning light)
ABS, TRAC and VSC ECU (Brake warning light)
GAUGE fuse
Turn signal flasher (Left turn side)
Turn signal flasher (Right turn side)
Light control rheostat (+B)
Light control rheostat (Signal)
Light control rheostat (Ground)
PANEL fuse
Airbag sensor assembly
MPX+B fuse
DOME+B fuse
HEAD±RH fuse
Igniter
Headlight beam leveling control ECU
Ground
Telltale light assembly (IG+)
Telltale light assembly (ODO/TRIP switch)
Telltale light assembly (Right turn signal)
Telltale light assembly (RESET switch)
Telltale light assembly (Left turn signal)
GroundWiring connector side No.1
1
1
2
3
4
5
6
7
8
10
11
12
13
14
15
16
17
1 1
1
2
3
4
5
6
9
12
13
14
15
16
18
22
1 1
1
3
4
8
9
10 U B A
± BODY ELECTRICALCOMBINATION METER
BE±85
2386 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

I04097
Battery Ignition
SwitchWarning Light
Wire Harness Side
I04098
Wire Harness Side
I04099
BatteryIgnition
SwitchWarning Light
Wire Harness Side BE±100
± BODY ELECTRICALCOMBINATION METER
2401 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
23. INSPECT REAR LIGHTS WARNING LIGHT
(See page DI±841)
(a) Disconnect the connector from the light failure sensor and
ground terminal 3 on the wire harness side connector.
(b) Start the engine, check that the warning light lights up.
If the warning light does not light up, inspect the bulb or wire har-
ness.
24. INSPECT LIGHT FAILURE SENSOR CIRCUIT
Disconnect connector from the light failure sensor and inspect
the connectors on the wire harness side as follows.
Tester connectionConditionSpecified condition
1 ± GroundConstantContinuity *
2 ± GroundConstantContinuity *
6 ± GroundConstantContinuity *
7 ± GroundConstantContinuity *
11 ± GroundConstantContinuity
12 ± GroundConstantContinuity *
5 ± GroundLight control switch OFFNo voltage
5 ± GroundLight control switch in TAIL or HEADBattery positive voltage
8 ± GroundIgnition switch in LOCK or ACCNo voltage
8 ± GroundIgnition switch ONBattery positive voltage
9, 10 ± GroundStop light switch OFFNo voltage
9, 10 ± GroundStop light switch ONBattery positive voltage
*: There is resistance because this circuit is grounded through
the bulb.
If circuit is as specified, replace the relay.
If circuit is not as specified, wiring diagram and inspect the cir-
cuits connected to other parts.
25. INSPECT ENGINE OIL LEVEL WARNING LIGHT
(a) Disconnect the connector from the switch.
(b) Run the engine.
(c) Turn the ignition switch ON, check that the warning light
lights up approximatery 40 seconds later.
If the warning light does not light up, inspect bulb or wire har-
ness.

I04102
ON OFF
I04103
ON OFF
I04104
Wire Harness Side
I01286
BatteryWarning Light
± BODY ELECTRICALCOMBINATION METER
BE±101
2402 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
26. INSPECT ENGINE OIL LEVEL WARNING SENSOR
(a) Check that continuity exists between terminals with the
switch to below 40 °C (104 °F). (Warning switch ON)
(b) Heat the switch to above 60 °C (140 °F) in an oil bath.
(c) Check that there is continuity between terminals with the
switch ON (float up).
(d) Check that there is no continuity between terminals with
the switch OFF (float down).
If operation is not as specified, replace the switch.
27. INSPECT ENGINE OIL LEVEL WARNING SENSOR
CIRCUIT
Disconnect the switch connector and inspect the connector on
wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundConstantContinuity
If continuity is not as specified, inspect the wire harness or
ground point.
28. INSPECT OPEN DOOR WARNING LIGHT
Disconnect the connector from the door courtesy switch and
ground terminal 1 on the wire harness side, and check that the
warning light lights up.
If the warning light does not light up, inspect the bulb or wire har-
ness.
29. INSPECT DOOR COURTESY SWITCH CONTINUITY
AND CIRCUIT (See page BE±60)

I04108
Wire Harness Side
I04109
Press
Sensing part
± BODY ELECTRICALCOMBINATION METER
BE±103
2404 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
35. INSPECT SEAT BELT BUCKLE SWITCH CIRCUIT
Driver side: (See page DI±830)
Passenger side: (See page DI±785)
Disconnect the switch connector and inspect the connector on
wire harness side, as shown.
Tester connectionConditionSpecified condition
4 ± GroundConstantContinuity
If continuity is not as specified, inspect the circuits connected
to other parts.
36. Passenger seat only:
INSPECT SEAT BELT WARNING OCCUPANT DETEC-
TION SENSOR CONTINUITY
Check that continuity exists between the terminals 1 and 2
when pressing the sensing part.
If operation is not as specified, replace the sensor.
37. Passenger seat only:
INSPECT SEAT BELT WARNING OCCUPANT DETEC-
TION SENSOR CIRCUIT (See page DI±785)

F06045
Reservoir Set Screw
Hydraulic Brake Booster
Oil Pressure
Sensor
No. 1 Accumulator
BracketNo. 2
Accumulator
Bracket
No. 1 Pump
Bracket
Actuator No. 1 TubeAccumulator

O±ring
Spring
Silencer Tube Grommet
No. 2 Piston
No. 1 PistonSnap Ring
BootClevis Reservoir
Cap
No. 2 Pump
Bracket Sleeve
Collar
Booster Pump Motor
Cushion Washer Actuator Hose
15 (155, 11)
54 (550, 36)
1.7 (17.5, 15.2 in.´lbf)
81 (830, 60)
Non±reusable part


Cushion Cushion
Collar
Cushion
25 (260, 19)
N´m (kgf´cm, ft´lbf) : Specified torqueSpacer

O±ring
Clamp

Wire Harness
± BRAKEHYDRAULIC BRAKE BOOSTER
BR±49
2157 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

BR0YV±02
F06048
SST
SST
F06961
F01657Pin
± BRAKEHYDRAULIC BRAKE BOOSTER
BR±51
2159 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
DISASSEMBLY
1. PLACE HYDRAULIC BRAKE BOOSTER IN VISE
Using SST, set the hydraulic brake booster in vise.
SST 09630±00014 (09631±00142),
09950±60010 (09951±00180, 09951±00190)
2. REMOVE RESERVOIR AND GROMMETS
(a) Remove the reservoir cap.
(b) Remove the 3 set screws and pull out the reservoir.
Torque: 1.7 N´m (17.5 kgf´cm, 15.2 in.´lbf)
(c) Remove the 3 grommets.
3. REMOVE CYLINDER BOOT
4. REMOVE OIL PRESSURE SENSOR
Using 30 mm deeper socket wrench and remove the oil pres-
sure sensor, spacer and O±ring.
Torque: 81 N´m (830 kgf´cm, 60 ft´lbf)
5. REMOVE PISTONS
(a) Pressing the piston in with a screwdriver, use a pin or an
equivalent to push the snap ring from the hole in the body
then remove it with another screwdriver.
(b) Remove the No. 1 and No. 2 piston, pulling straight out,
not at an angle.
NOTICE:

If pulled out and installed at an angle, there is a possi-
bility that the cylinder bore could be damaged.

At the time of reassembly, be careful not to damage
the rubber lips on the pistons.
6. DISCONNECT ACTUATOR HOSE
7. REMOVE 3 BOLTS, 2 HANGERS AND CLAMP

BR0K1±07
F02813
Front Speed Sensor
5.0 (51, 44 in.´lbf)
5.0 (51, 44 in.´lbf)
8.0 (82, 71 in.´lbf)
N´m (kgf´cm, ft´lbf) : Specified torque
± BRAKEFRONT SPEED SENSOR
BR±57
2165 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
FRONT SPEED SENSOR
COMPONENTS