ABS LEXUS GS400 2000 Service User Guide

I04253

Meter Circuit Plate ± 2
Combination Meter ECU
SLIP Indicator
TRAC OFF Indicator
Window Washer Level Warning
ABS Warning
VSC Warning
Brake Fluid Level Warning
ECT SNOW Indicator
Low Oil Pressure Warning
ECT PWR Indicator
Discharge Warning
CRUISE MAIN Indicator
Seat Belt Warning
Rear Light Indicator
Headlight Leveling Indicator
SRS Warning
Open Door Warning
Fog Light IndicatorA/T 2 Indicaor
Engine Oil Level Indicator
Malfunction Indicator
Fuel Level Indicator
Headlight Indicator (USA)
Taillight Indicator (CANADA) ODO/
TRIP
Display
PanelIG+
SLIP
TRC OFF
WASHER
ABS
VSC
BRAKE
ECT SNOW
OIL P
ECT PWR
CHARGE
CRUISE
SEAT BELT
Rr LIGHT
HEAD LVL
AIRBAG
SRS +B
DOOR
FR FOG
COM1
SEG30
TEST1
TEST2
TEST3
GroundCHECK
ENG
IG+
FUEL
IG+
BEAM±
BEAM+ SRS +BTAIL A/T R
A/T L
A/T N
A/T D
OIL LVLDIM+
A/T 2
A/T 3
A/T 4F12
A/T PF11
F10
F9
F8
F5
F4
F2
F1
C7
C5
C3
D12
D8 E11
E10
E9
E8
E7
E6
J1
J33
D6
D4Hi±Beam Indicator
D2 E20
E19
E18
E17
E16
E15
E14
E13
E12
E3
E1 E5
E4A/T 3 Indicaor
A/T 4 Indicaor
A/T P Indicaor
A/T R Indicaor
A/T L Indicaor
A/T N Indicaor
A/T D Indicaor
T1
T2
T3
T4
~~
D10 BE±88
± BODY ELECTRICALCOMBINATION METER
2389 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

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

± BRAKETROUBLESHOOTING
BR±3
2111 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) Noise from brakes
1. Pad (Cracked or distorted)
2. Installation bolt (Loose)
3. Disc (Scored)
4. Pad support plate (Loose)
5. Sliding pin (Worn)
6. Pad (Dirty)
7. Pad (Glazed)
8. Tension or return spring (Faulty)
9. Anti±squeal shim (Damaged)
10.Shoe hold±down spring (Damaged)BR±15
BR±24
BR±15
BR±24
BR±18
BR±27
BR±18
BR±18
BR±15
BR±24
BR±15
BR±24
BR±33
BR±18
BR±27
BR±33
Noise from hydraulic brake booster
(Abnormal pump motor operation noise)Accumulator bracket clearance (Out or adjustment)BR±56
Brake warning light lights up*1
(Parking brake pedal released)
1. Brake fluid level
2. Hydraulic brake booster power supply system (Faulty)BR±38
Brake warning light lights up and brake warning buzzer sounds*2Hydraulic brake booster power supply system (Faulty)BR±38
ABS warning light lights up*31. Anti±lock brake system (Faulty)
2. Hydraulic brake booster power supply system (Faulty)
BR±38
*1, *3: The light may stay on for about 60 seconds after the engine has been started. It is normal if it goes
out after a while.
*
2, *3: Depressing the brake pedal repeatedly may turn on the warning light and buzzer. It is normal if the
light goes out and the buzzer stops sounding after a few seconds.
*
3: While ABS warning light is ON, both VSC warning light and VSC OFF indicator light come on.

BR±40
± BRAKEHYDRAULIC BRAKE BOOSTER
2148 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(4) When the solenoids are OFF, after depressing the
brake pedal again and check that the brake pedal
can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(g) Inspect the front ABS solenoid operation.
(1) Select ºSFRHº and ºSFLHº on the LEXUS hand±
held tester.
(2) With ºSFRHº and ºSFLHº turned ON simultaneously
with the LEXUS hand±held tester, depress the
brake pedal with stable force and check that the
brake pedal cannot be depressed.
HINT:
To protect the solenoids, hand±held tester turns OFF automati-
cally 2 sec. after every solenoid has been turned ON.
If the pedal can be depressed, replace the hydraulic brake
booster.
(3) Once, release the brake pedal when the solenoids
are OFF, check that the brake pedal can be de-
pressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(4) Once, release the brake pedal. After depressing
and holding the brake pedal with stable force, turn
the SFRH and SFRR solenoids ON simultaneously.
HINT:
To protect the solenoids, hand±held tester turns OFF automati-
cally 2 sec. after every solenoid has been turned ON.
(5) When the solenoids are OFF, check that the brake
pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(6) Once, release the brake pedal. After depressing
and holding the brake pedal with stable force, turn
the SFLH and SFLR solenoids ON simultaneously.
HINT:
To protect the solenoids, hand±held tester turns OFF automati-
cally 2 sec. after every solenoid has been turned ON.
(7) When the solenoids are OFF, check that the brake
pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(h) Jack up and support the vehicle.
(i) Release the parking brake pedal.
(j) Shift the shift lever to ºNº position and check that the rear
wheels by rotating them by hand.
(k) Inspect the rear TRAC & VSC solenoid operation.
(1) Select the ºSA3º and ºSTRº on the LEXUS hand±
held tester.

± BRAKEHYDRAULIC BRAKE BOOSTER
BR±41
2149 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(2) Turn the ºSA3º and ºSTRº ON simultaneously with
the LEXUS hand±held tester, and check that the
rear wheels by does not rotate by hand.
HINT:
When rotating the wheel fast, the fail±safe function is activated
and judgement cannot be made properly. So rotate the wheel
as slowly as possible.
If the rear wheels rotate, replace the hydraulic brake booster.
(3) Turn the ºSA3º and ºSTRº OFF simultaneously, and
check that the rear wheels by rotating them by
hand.
HINT:

To protect the solenoids, LEXUS hand±held tester turns
OFF automatically 2 sec. after every solenoid has been
turned ON.

When rotating the wheel fast, the fail±safe function is acti-
vated and judgement cannot be made properly. So rotate
the wheel as slowly as possible.
NOTICE:
When operating it continuously, set the interval of more
than 20 secs.
If the rear wheels stop, replace the hydraulic brake booster.
(l) Inspect the right rear ABS solenoid.
(1) Select the ºSA3º, ºSTRº and ºSRRHº, on the LEXUS
hand±held tester.
(2) Turn the ºSA3º, ºSTRº and ºSRRHº ON simulta-
neously with the LEXUS hand±held tester, and
check that the right rear wheel by rotating it by hand.
HINT:

To protect the solenoids, LEXUS hand±held tester turns
OFF automatically 2 sec. after every solenoid has been
turned ON.

When rotating the wheel fast, the fail±safe function is acti-
vated and judgement cannot be made properly. So rotate
the wheel as slowly as possible.

When solenoid is OFF, the wheel might stop temporarily.
However if the wheel rotates again, the function works
normally.
If the rear wheels stop, replace the hydraulic brake booster.
(3) Turn the ºSA3º, ºSTRº and ºSRRHº OFF, and check
that the right rear wheel by rotating it by hand.
HINT:

To protect the solenoids, LEXUS hand±held tester turns
OFF automatically 2 sec. after every solenoid has been
turned ON.

When rotating the wheel fast, the fail±safe function is acti-
vated and judgement cannot be made properly. So rotate
the wheel as slowly as possible.
If the right rear wheel stop, replace the hydraulic brake booster.

BR±42
± BRAKEHYDRAULIC BRAKE BOOSTER
2150 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(4) Depress the pedal with stable force, then turn the
ºSRRHº and ºSRRRº ON simultaneously.
(5) When the solenoids are ON, check that the right
rear wheel by rotating it by hand.
(m) Inspect the left rear ABS solenoid operation.
(1) Select the ºSA3º, ºSTRº and ºSRLHº on the LEXUS
hand±held tester.
(2) Turn the ºSA3º, ºSTRº and ºSRLHº ON with LEXUS
hand±held tester, and check that the left rear wheel
by rotating it by hand.
HINT:
When rotating the wheel fast, the fail±safe function is activated
and judgement cannot be made properly. So rotate the wheel
as slowly as possible.
If the rear wheels stop, replace the hydraulic brake booster.
(3) Turn the ºSA3º, ºSTRº and ºSRLHº OFF and check
that the left rear wheel by rotating it by hand.
HINT:

To protect the solenoids, LEXUS hand±held tester turns
OFF automatically 2 sec. after every solenoid has been
turned ON.

When rotating the wheel fast, the fail±safe function is acti-
vated and judgement cannot be made properly. So rotate
the wheel as slowly as possible.

When solenoid is OFF, the wheel might stop temporarily.
However if the wheel rotates again, the function works
normally.
If the left rear wheel stop, replace the hydraulic brake booster.
(4) Depress the pedal with stable force, then turn the
ºSRLHº and ºSRLRº ON simultaneously.
HINT:
To protect the solenoids, LEXUS hand±held tester turns OFF
automatically 2 sec. after every solenoid has been turned ON.
(5) When the solenoids are ON, check that the left rear
wheel by rotating it by hand.
HINT:
When rotating the wheel fast, the fail±safe function is activated
and judgement cannot be made properly. So rotate the wheel
as slowly as possible.
(n) Lower the vehicle.
(o) Disconnect the LEXUS hand±held tester.

F06049
F02821
Hydraulic Brake
BoosterSub±Wire harness S (SST)
FRONT
REAR
AIR BLEEDActuator Checker (SST)
± BRAKEHYDRAULIC BRAKE BOOSTER
BR±43
2151 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. IN CASE OF USING ABS ACTUATOR CHECKER:
INSPECT HYDRAULIC BRAKE BOOSTER OPERA-
TION
(a) Inspect the battery positive voltage.
Battery positive voltage: 10 ± 14 V
(b) Disconnect the 2 connectors from hydraulic brake boost-
er.
(c) Connect the actuator checker (SST) to the hydraulic
brake booster side wire harness via the sub±wire harness
S (SST), as shown in the chart below.
SST 09990±00150, 09990±00480
HINT:
Connect the connector with the label of ºFRONTº attached to
the connector of actuator checker.
(d) Connect the red cable of the checker to the battery posi-
tive (+) terminal and the black cable to the negative (±) ter-
minal.
(e) Place ºSHEET Gº (SST) of ºFRONTº on actuator checker.
SST 09990±00240
(f) Turn the ignition switch OFF, depress the brake pedal
more than 40 times.
(g) Check that the brake pedal becomes heavy to depress.
If the pedal does not become to be heavy to depress, check and
replace the brake line and hydraulic brake booster.
(h) Turn the ignition switch ON, check the pump motor opera-
tion noise.
If the pump motor does not operate, check and replace the wire
harness and pump motor.

F04706
F02828
F02827
BR±44
± BRAKEHYDRAULIC BRAKE BOOSTER
2152 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(i) Inspect the front TRAC & VSC solenoid operation.
(1) Push in and hold the ºSA1º and ºSA2º switches si-
multaneously, depress strongly and hold the brake
pedal with stable force.
NOTICE:
Do not keep the ºSA1º and ºSA2º pushed down for more
than 10 seconds. When operating it continuously, set the
interval of more than 20 seconds.
(2) Check that the brake pedal cannot be depressed.
If the pedal can be depressed, replace the hydraulic brake
booster.
(3) Release the ºSA1º switch and check that the brake
pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(4) Release the ºSA2º switch and check that the brake
pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(j) Inspect the right front ABS solenoid operation.
(1) Turn the selector switch to ºRHº position.
(2) Push and hold in the MAIN push switch and ºSA2º
switch simultaneously, depress and hold the brake
pedal with stable force.
NOTICE:
Do not keep the MAIN push switch and ºSA2º switch
pushed down for more than 10 seconds. When operating
it continuously, set the interval of more than 20 seconds.
(3) Check that the brake pedal cannot be depressed.
If the pedal can be depressed, replace the hydraulic brake
booster.
(4) Release the MAIN push switch and ºSA2º switch si-
multaneously and check that the brake pedal can
be depressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(5) Release the brake pedal.
(6) Depress and hold the brake pedal with stable force,
push and hold in MAIN push switch.
NOTICE:
Do not keep the MAIN push switch pushed down for more
than 10 seconds. When operating it continuously, set the
interval of more than 20 seconds.
(7) Check that the brake pedal cannot be depressed.
If the pedal can be depressed, replace the hydraulic brake
booster.

F04707
F02829
± BRAKEHYDRAULIC BRAKE BOOSTER
BR±45
2153 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(8) Release the MAIN push switch, and check that the
brake pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(9) Release the brake pedal.
(k) Inspect the left front ABS solenoid operation.
(1) Turn the selector switch to ºLHº position.
(2) Push and hold in the MAIN push switch and ºSA1º
switch simultaneously, depress and hold the brake
pedal with stable force.
NOTICE:
Do not keep the MAIN push switch and ºSA1º switch
pushed down for more than 10 seconds. When operating
it continuously, set the interval of more than 20 seconds.
(3) Check that the brake pedal cannot be depressed.
If the pedal can be depressed, replace the hydraulic brake
booster.
(4) Release the MAIN push switch and ºSA1º switch si-
multaneously, and check that the brake pedal can
be depressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(5) Release the brake pedal.
(6) Depress and hold the brake pedal with stable force,
push and hold in MAIN push switch.
NOTICE:
Do not keep the MAIN push switch pushed down for more
than 10 seconds. When operating it continuously, set the
interval of more than 20 seconds.
(7) Check that the brake pedal cannot be depressed.
If the pedal can be depressed, replace the hydraulic brake
booster.
(8) Release the MAIN push switch, and check that the
brake pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(9) Release the brake pedal.
(l) Turn the ignition switch OFF, then reconnect the connec-
tor of sub±wire harness from the one with label of
ºFRONTº to ºREARº.
(m) Place ºSHEET Gº of ºREARº on the actuator checker.
(n) Jack up and support the vehicle.
(o) Start the engine and run it at idle.

F02830
F02831
BR±46
± BRAKEHYDRAULIC BRAKE BOOSTER
2154 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(p) Inspect the rear TRAC & VSC solenoid.
(1) Release the parking brake pedal and shift the shift
lever to ºLº position.
(2) Push and hold the ºSA3º switch and ºSTRº switch
simultaneously.
NOTICE:

Do not keep the ºSTRº switch pushed down for more
than 10 seconds.

Do not keep the ºSA3º switch pushed down for more
than 5 seconds.

When operating it continuously, set the interval of
more than 20 seconds.
(3) Check that the rear wheels stop.
If the rear wheels rotate, replace the hydraulic brake booster.
(4) Release the ºSA3º switch and ºSTRº switch simulta-
neously.
(5) Check that the rear wheels rotate.
If the rear wheels stop, replace the hydraulic brake booster.
(q) Inspect the right rear ABS solenoid.
(1) Turn the selector switch to ºRHº position.
(2) Depress the brake pedal several times and release
the brake pedal when the pump begins rotating.
Wait until the pump stops.
(3) Turn the ignition switch OFF.
(4) Depress the brake pedal with a force of 343 N (35
kgf, 77 lbf), record the fluid surface in the reservoir
tank of the hydraulic brake booster.
(5) Press the MAIN push switch for 10 sec., and check
that the fluid surface in the reservoir tank of the hy-
draulic brake booster does not rise up at this time.
If the fluid surface level rises up, replace the hydraulic brake
booster.
NOTICE:
Do not press MAIN push switch for more than 10 sec. When
operating the switch continuously, do it an interval of more
than 20 seconds.
(6) Start the engine and run it at idle.
(7) Depress the brake pedal.
(8) Release the parking brake pedal and shift the shift
lever to ºLº position.
(9) Once, release the brake pedal. After depressing the
brake pedal with stable force, then push and hold
MAIN push switch.
(10) Check that the right rear wheel rotates.
If the right rear wheel stops, replace the hydraulic brake boost-
er.