Page 376 of 1111

I04079
Connector ºCº Connector ºDº
Connector ºFº Connector ºEº
Connector ºGº
1 131 13
1 201 12
± BODY ELECTRICALCOMBINATION METER
BE±93
2394 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
2. INSPECT COMBINATION METER CIRCUIT PLATE
Warning light circuit plate:
(a) Remove meter cover.
(b) Disconnect connectors ºCº, ºDº, ºEº, ºFº and ºGº from the
meter circuit plate and inspect the connectors on the wire
harness side as shown in the table.
Tester connectionCheck indicator lightSpecified condition
D10 (+) ± D12 (±)Fuel level warning lightContinuity
D6 (+) ± D8 (±)Headlight indiactor light (USA)
Taillight indiactor light (CANADA)Continuity
D2 (+) ± D4 (±)Hi±beam indicator lightContinuity
C3 (+) ± C7 (±)Engine oil level warning lightContinuity
C3 (+) ± C5 (±)Malfunction indicator lightContinuity
E19 (±) ± E20 (+)Slip warning lightContinuity
E18 (±) ± E20 (+)TRAC OFF indicator lightContinuity
E17 (±) ± E20 (+)Window washer level warning lightContinuity
E16 (±) ± E20 (+)ABS warning lightContinuity
E15 (±) ± E20 (+)VSC OFF indicator lightContinuity
E14 (±) ± E20 (+)Brake warning lightContinuity
E13 (±) ± E20 (+)ECT SNOW indicator lightContinuity
E12 (±) ± E20 (+)Low oil pressure warning lightContinuity
E11 (±) ± E20 (+)ECT PWR indicator lightContinuity
E10 (±) ± E20 (+)Discharge warning lightContinuity
E9 (±) ± E20 (+)CRUISE MAIN indicator lightContinuity
E8 (±) ± E20 (+)Seat belt warning lightContinuity
E7 (±) ± E20 (+)Rear Lights warning lightContinuity
E6 (±) ± E20 (+)Headlight leveling indiactorContinuity
E4 (+) ± E5 (±)SRS warning lightContinuity
E3 (±) ± E4 (+)Open door warning lightContinuity
F4 (±) ± F12 (+)A/T shift indicator light (L)Continuity
F11 (±) ± F12 (+)A/T shift indicator light (2)Continuity
F10 (±) ± F12 (+)A/T shift indicator light (3)Continuity
F8 (±) ± F12 (+)A/T shift indicator light (P)Continuity
Page 381 of 1111

I04091
F
E1
2
1/2
I04094
A
D
C
B
I01277
Battery Ignition
SwitchWarning Light
Wire Harness Side
1 BE±98
± BODY ELECTRICALCOMBINATION METER
2399 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
13. INSPECT FUEL SUB SENDER GAUGE RESISTANCE
Measure the resistance between terminals 1 and 2 for each
float position.
Float position mm (in.)Resistance (W)
F: Approx. 9.5 (0.37) ± 3 (0.12)Approx. 2.0 ± 1.0
1/2: Approx. 110.5 (4.35) ± 3 (0.12)Approx. 33.0 ± 3.0
E: Approx. 206.5 (8.13) ± 3 (0.12)Approx. 61.3 ± 1.0
If resistance value is not as specified, replace the sub sender
gauge.
14. INSPECT ENGINE COOLANT TEMPERATURE RE-
CEIVER GAUGE OPERATION (See page DI±754)
15. INSPECT ENGINE COOLANT TEMPERATURE RE-
CEIVER GAUGE RESISTANCE
Measure the resistance between terminals with fixing pointer to
the stopper.
Tester connectionResistance (W)
A ± B140 ± 185
C ± D130 ± 175
If resistance value is not as specified, replace the receiver
gauge.
HINT:
This circuit includes the diode.
If resistance value is not as specified, replace the receiver
gauge.
16. INSPECT LOW OIL PRESSURE WARNING LIGHT
(a) Disconnect the connector from the warning switch and
ground terminal on the wire harness side connector.
(b) Turn the ignition switch ON and check that the warning
light lights up.
If the warning light does not light up, test the bulb.
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 432 of 1111
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)
Page 434 of 1111

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
Page 533 of 1111
A11125
Throttle Body and Intake Air Connector AssemblyWater Bypass Hose
PCV Hose
EVAP Hose
Gasket
Air Assist Hose
Vacuum
Hose
PS Air Hose
Air Intake Chamber
Engine Wire
Clamp
Drive Belt
TensionerClamp Bracket
Ground StrapFuel Pressure
Pulsation Damper Clamp Bracket
Water Bypass
Outlet
No.1 Water Bypass Pipe
No.3 Timing Belt Cover O±Ring
Oil Filler CapFuel Inlet Pipe
PS Air Hose
Hose
Clamp
Timing Belt
Tensioner
PS Pump Stay
Oil Dipstick
and Guide
for A/T
PS Vane Pump Water Bypass Hose
28 (280, 21)
Engine Wire
O±Ring
No.2 Timing Belt Cover
GasketGasket
21 (210, 15)
32.5 (325, 24)
Gasket
Gasket
Engine Wire
Clamp
O±Ring O±RingOil Dipstick and
Guide for Engine
27 (270, 20)
58 (590, 43)39.2 (400, 29)N´m (kgf´cm, ft´lbf) : Specified torque
Non±reusable Part
Dust BootEngine Wire
Clamp
No.2 Vacuum Pipe
Hose Clamp
Vacuum Control
Valve Set
EM±30
± ENGINE MECHANICAL (2JZ±GE)CYLINDER HEAD
1384 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
Page 536 of 1111

EM0D1±05
A11132
Compression Tester
± ENGINE MECHANICAL (2JZ±GE)COMPRESSION
EM±3
1357 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
COMPRESSION
INSPECTION
HINT:
If there is lack of power, excessive oil consumption or poor fuel
economy, measure the compression pressure.
1. WARM UP AND STOP ENGINE
Allow the engine to warm up to normal operating temperature.
2. REMOVE ENGINE COVER
Remove the 4 nuts and engine cover.
3. DISCONNECT IGNITION COILS AND HIGH±TENSION
CORD SET ASSEMBLY (See page IG±7)
4. REMOVE SPARK PLUGS
5. DISCONNECT INJECTOR CONNECTORS
6. CHECK CYLINDER COMPRESSION
(a) Insert a compression tester into the spark plug hole.
(b) While cranking the engine, measure the compression
pressure.
HINT:
Always use a fully charged battery to obtain engine revolutions
of 250 rpm or more.
(c) Repeat steps (a) through (b) for each cylinder.
NOTICE:
This measurement must be done in as short a time as pos-
sible.
Compression:
1,324 kPa (13.5 kgf/cm
2, 192 psi) or more
Minimum pressure:
1,079 kPa (11.0 kgf/cm
2, 156 psi)
Difference between each cylinder:
98 kPa (1.0 kgf/cm
2, 14 psi) or less
(d) If the cylinder compression in 1 or more cylinders is low,
pour a small amount of engine oil into the cylinder through
the spark plug hole and repeat steps (a) through (b) for
the cylinder with low compression.
If adding oil helps the compression, it is likely that
the piston rings and/or cylinder bore are probably
worn or damaged.
If pressure stays low, a valve may be sticking or
seating improper, or there may be leakage past the
gasket.
Page 540 of 1111

A02732
(a)
(b) (c)
(d)(d)
(c) (b)
A02811
A02733
Clamp Bracket
A11123
5 mm
Hexagon
Wrench
± ENGINE MECHANICAL (2JZ±GE)CYLINDER HEAD
EM±35
1389 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
20. DISCONNECT ENGINE WIRE FROM CYLINDER HEAD
(a) Disconnect the ground strap from the cylinder head.
(b) Disconnect the 2 water bypass hoses from the hose
clamps on the cylinder head and oil filter bracket.
(c) Remove the 2 bolts and hose clamps.
(d) Disconnect the heated oxygen sensor (bank 2 sensor 1)
connector and engine wire clamp from the hose clamps.
(e) Disconnect the heated oxygen sensor (bank 1 sensor 1)
connector.
(f) Disconnect the crankshaft position sensor connector.
(g) Disconnect the generator connector.
(h) Remove the bolt and clamp bracket, and disconnect the
engine wire from the water pump.
(i) Disconnect the 2 ground terminals from the intake man-
ifold.
(j) Disconnect the 2 engine wire clamps from the No.1 oil
pipe and clamp bracket on the intake manifold.
(k) Remove the bolt and clamp bracket.
(l) Disconnect the ECT sensor connector.
(m) Remove the 2 knock sensor connectors.
(n) Remove the oil pressure switch connector.
(o) Remove the oil level sensor connector.
(p) Remove the starter connector.
(q) Remove the 6 injector connectors.
(r) Remove the camshaft timing oil control valve connector.
(s) Remove the camshaft position sensor connector.
(t) Using a 5 mm hexagon wrench, remove the bolt holding
the engine wire protector to the No.2 cylinder head cover.
(u) Remove the 3 nuts, and disconnect the engine wire pro-
tector from the intake manifold.
21. REMOVE FUEL PRESSURE PULSATION DAMPER
(See page SF±26)