Page 302 of 1111

± BODY ELECTRICALTROUBLESHOOTING
BE±5
2306 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) ºHI±Beamº does not light (All).
1. Headlight Dimmer Switch
2. Daytime Running Light Main Relay
3. Wire HarnessBE±37
BE±37
±
ºHI±Beamº does not light (One side).
1. Bulb
2. H±LP L±UPR Fuse
3. H±LP R±UPR Fuse
4. Daytime Running Light No.3 Relay
5. Wire Harness±
BE±21
BE±21
BE±37
±
ºFlashº does not light.
1. Headlight Dimmer Switch
2. Daytime Running Light Main Relay
3. Wire HarnessBE±37
BE±37
±
Headlight does not come on.
1. Headlight Control Relay
2. Daytime Running Light Main Relay
3. Daytime Running Light No.2, 3, 4 Relay
4. Headlight Dimmer Switch
5. Light Control Switch
6. Wire Harness
7. *Light Control ECU
8. BulbBE±37
BE±37
BE±37
BE±37
BE±37
±
±
±
Headlight does not come on with light control switch in HEAD.
1. Light Control Switch
2. *Light Control ECU
3. Wire HarnessBE±37
±
±
Headlight does not go out with light control switch in OFF.
1. Headlight Control Relay
2. *Light Control ECU
3. Wire HarnessBE±37
±
±
Headlight flickers.
1. Bulb
2. *Light Control ECU
3. Wire Harness±
BE±37
±
Headlight is dark.
1. Bulb
2. *Light control ECU
3. Wire Harness±
±
±
Taillight does not come on with light control switch in TAIL.
1. Taillight Control Relay (Instrument Panel J/B)
2. Light Control Switch
3. Wire HarnessBE±37
±
±
Taillight does not go out with light control switch in OFF.
1. Taillight Control Relay
2. Light Control Switch
3. Wire HarnessBE±37
BE±37
±
Headlight does not come on with engine running and light control
switch in OFF.
1. ECU±B Fuse
2. GAUGE Fuse
3. Daytime Running Light Main Relay
4. Daytime Running Light No.2, 3, 4 Relay
5. Generator L Terminal
6. Parking Brake Switch
7. Wire HarnessBE±21
BE±21
BE±37
BE±37
DI±853
BE±92
±
*: HID Type
Page 324 of 1111

I01260
21
3 42
41
3
I01200
2 1
35
2 5
1 3
I04037
Wire Harness Side
h±10±1±A
± BODY ELECTRICALHEADLIGHT AND TAILLIGHT SYSTEM
BE±41
2342 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
11. INSPECT HEADLIGHT DIMMER ( DAYTIME RUNNING
LIGHT NO.2) RELAY CONTINUITY
ConditionTester connectionSpecified condition
Constant1 ± 4
2 ± 4Continuity
Apply B+ between
terminals 2 and 4.1 ± 3 ± 4Continuity
If continuity is not as specified, replace the relay.
12. INSPECT HEADLIGHT DIMMER (DAYTIME RUNNING
LIGHT NO.2) RELAY CIRCUIT
(See page BE±21)
13. INSPECT TAILLIGHT CONTROL RELAY CONTINUITY
ConditionTester connectionSpecified condition
Constant1 ± 2Continuity
Apply B+ between
terminals 1 and 2.3 ± 5Continuity
If continuity is not as specified, replace the relay.
14. INSPECT TAILLIGHT CONTROL RELAY CIRCUIT
(See page DI±845 and BE±21)
15. INSPECT DAYTIME RUNNING LIGHT MAIN RELAY
CIRCUIT
Disconnect the connector from the relay and inspect the con-
nector on the wire harness side.
Tester connectionConditionSpecified condition
2 ± GroundLight control switch OFF or TAILNo continuity
2 ± GroundLight control switch HEADContinuity
4 ± GroundParking brake switch OFF
(Parking brake pedal released)No continuity
4 ± GroundParking brake switch ON
(Parking brake pedal depressed)Continuity
6 ± GroundConstantContinuity
8 ± GroundHeadlight dimmer switch LOW beamNo continuity
Page 363 of 1111
BE0HH±07
I01359
Brake Master Cylinder
Brake Fluid Level
Warning Switch
Combination Meter
and Telltale Light
Assembly
Airbag Sensor Assembly Parking Brake Switch
Driver Side
Junction Block
GAUGE Fuse
SRS±B FuseIgnition Switch
ECM
Washer Tank
Washer Level
Warning Switch Engine Room No.1
Junction Block
MPX±B Fuse
Seat Belt Buckle Switch
Rheostat Light Control
ABS, TRAC and VSC ECU
Clock Assembly
Passenger Seat Belt
Waning Light
BE±80
± BODY ELECTRICALCOMBINATION METER
2381 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
COMBINATION METER
LOCATION
The vehicle shown in this illustration is ºGS400º.
All components of ºGS300º other than the ones used for engine are same as ºGS400º.
Page 382 of 1111

I01278
I01279
Battery Ignition
SwitchWarning Light
I04095
OFF
ON
I04096
± BODY ELECTRICALCOMBINATION METER
BE±99
2400 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
17. INSPECT LOW OIL PRESSURE SWITCH CONTINUITY
(a) Disconnect the connector from the switch.
(b) Check that continuity exists between terminal and ground
with the engine stopped.
(c) Check that no continuity exists between terminal and
ground with the engine running.
HINT:
Oil pressure should be over 24.5 kPa (0.25 kgf/cm
2, 3.55 psi).
If operation is not as specified, replace the switch.
18. INSPECT BRAKE WARNING LIGHT
(a) Disconnect the connector from the brake fluid warning
switch.
(b) Release the parking brake pedal.
(c) Connect the terminals on the wire harness side of the lev-
el warning switch connector.
(d) Start the engine, check that the warning light lights up.
If the warning light does not light up, test the bulb or wire har-
ness.
19. INSPECT BRAKE FLUID LEVEL WARNING SWITCH
CONTINUITY
(a) Remove the reservoir tank cap and strainer.
(b) Disconnect the connector.
(c) Check that no continuity exists between the terminals with
the switch OFF (float up).
(d) Use siphon, etc. to take fluid out of the reservoir tank.
(e) Check that continuity exists between the terminals with
the switch ON (float down)
(f) Pour the fluid back in the reservoir tank.
If operation is not as specified, replace the switch.
20. INSPECT BRAKE FLUID LEVEL WARNING SWITCH
CIRCUIT (See page DI±835)
21. INSPECT PARKING BRAKE SWITCH CONTINUITY
(a) Check that continuity exists between the terminal and
switch body with the switch ON (switch pin released).
(b) Check that no continuity exists between the terminal and
switch body with the switch OFF (switch pin pushed in).
If operation is not as specified, replace the switch or inspect
ground point.
22. INSPECT PARKING BRAKE SWITCH CIRCUIT
(See page DI±796)
Page 388 of 1111
F01619
BR0JD±03
F01620
Adjusting Nut
Lock Nut
± BRAKEPARKING BRAKE PEDAL
BR±11
2119 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
PARKING BRAKE PEDAL
ON±VEHICLE INSPECTION
1. CHECK PARKING BRAKE PEDAL TRAVEL
Depress the parking brake pedal all the way and count the num-
ber of clicks.
Parking brake lever travel at 294 N (30 kgf, 66.1 Ibf):
7 ± 9 clicks
2. IF NECESSARY, ADJUST PARKING BRAKE
HINT:
Before adjusting the parking brake, make sure that the rear
brake shoe clearance has been adjusted. For shoe clearance
adjustment see page BR±37.
(a) Loosen the lock nut and turn the adjusting nut until the
pedal travel is correct.
(b) Tighten the lock nut.
Torque: 5.4 N´m (55 kgf´cm, 48 in.´lbf)
Page 389 of 1111
BR0JE±03
F07241
No. 1 Safety Pad
No. 1 Under Cover
Front Door Scuff Plate End Pad
Parking Brake Switch
Parking Brake Pedal
AssemblyParking Brake WireAdjusting NutLock Nut
13 (130, 9)
5.4 (55, 48 in.´lbf)
No. 7 Heater to Register Duct
N´m (kgf´cm, ft´lbf) : Specified torque BR±12
± BRAKEPARKING BRAKE PEDAL
2120 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
COMPONENTS
Page 390 of 1111
BR0JF±03
± BRAKEPARKING BRAKE PEDAL
BR±13
2121 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REMOVAL
1. REMOVE FRONT DOOR SCUFF PLATE, END PAD, NO. 1 UNDER COVER, NO. 1 SAFETY PAD
AND NO. 7 HEATER TO REGISTER DUCT (See page BO±88)
2. REMOVE PARKING BRAKE PEDAL ASSEMBLY
(a) Disconnect the parking brake switch connector.
(b) Remove the 2 bolts, and disconnect the parking brake release lever from the safety pad.
Torque: 5.4 N´m (55 kgf´cm, 48 in.´lbf)
(c) Remove the lock nut and the adjusting nut from the parking brake wire.
(d) Remove the parking brake wire.
(e) Remove the 2 bolts, 2 nuts and parking brake pedal assembly.
Torque: 13 N´m (130 kgf´cm, 9 ft´lbf)
3. REMOVE PARKING BRAKE SWITCH
Remove the screw and parking brake switch from the parking brake pedal assembly.
Page 391 of 1111
BR0JG±02
BR±14
± BRAKEPARKING BRAKE PEDAL
2122 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSTALLATION
Installation is in the reverse order of removal (See page BR±13).
HINT:
After the installation, check and adjust parking brake pedal travel (See page BR±11).