2000 LEXUS GS400 Service Repair Manual

BE±2
± BODY ELECTRICALBODY ELECTRICAL SYSTEM
2303 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. MICRO COMPUTER PRESET DRIVING POSITION SYSTEM
Power Seat Control System
Power Mirror Control System
Power Tilt and Telescopic Steering System
If the battery negative (±) terminal is disconnected, the preset driving positions stored in memory are erased,
so be sure to note the positions and reset them after the battery terminal is reconnected.
5. AUDIO SYSTEM

If the negative (±) terminal cable is disconnected from the battery, the preset AM, FM 1 and FM 2 sta-
tions stored in memory are erased, so be sure to note the stations and reset them after the negative
(±) terminal cable is reconnected to the battery.

If the negative (±) terminal cable is disconnected from the battery, the ºANTI±THEFT SYSTEMº will
operate when the cable is reconnected, but the radio, tape player and CD player will not operate. Be
sure to input the correct ID number so that the radio, tape player and CD player can be operated again.
6. MOBILE COMMUNICATION SYSTEM
If the vehicle is equipped with a mobile communication system, refer to precautions in the IN section.

BE0GU±05
I01361
Ignition Switch
Buckle Switch
Driver Side Junction Block

ECU±IG Fuse
Electric Tension Reducer Solenoid
BE±104
± BODY ELECTRICALELECTRIC TENSION REDUCER SYSTEM
2405 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
ELECTRIC TENSION REDUCER SYSTEM
LOCATION

BE0GV±04
I04110
(b) (d)
Slowly
RetractedRetracted
More Quickly
I04111
Wire Harness Side
± BODY ELECTRICALELECTRIC TENSION REDUCER SYSTEM
BE±105
2406 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT TENSION REDUCER SOLENOID OPERA-
TION
(a) Connect the positive (+) lead from the battery to terminal
1, and negative (±) lead to terminal 2.
(b) Pull the belt upward and check that the belt is slowly re-
tracted when released.
(c) Disconnect the lead from the battery.
(d) Pull the belt upward and check that the belt is retracted
more quickly when released than in (b).
HINT:
Do not tilt the retractor.
If the operation is not as specified, replace the front seat outer
belt assembly.
2. INSPECT TENSION REDUCER SOLENOID CIRCUIT
Disconnect the tension reducer solenoid connector and inspect
the connector on wire harness side, as shown.
Tester connectionConditionSpecified condition
2 ± GroundBuckle switch position
OFF (belt unfastened)No continuity
2 ± GroundBuckle switch position
ON (belt fastened)Continuity
1 ± GroundIgnition switch ACC or LOCKNo voltage
1 ± GroundIgnition switch ONBattery positive voltage
If the circuit is specified, replace the front seat outer belt assem-
bly.
If the circuit is not as specified, inspect the circuits connected
to other parts.

I04107
12
4
OFF
ON
I04108
Wire Harness Side BE±106
± BODY ELECTRICALELECTRIC TENSION REDUCER SYSTEM
2407 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. INSPECT SEAT BELT BUCKLE SWITCH CONTINUITY
(a) Check that continuity exists between the terminals 1 and
4 on the switch side connector with the switch ON (belt
fastened).
(b) Check that continuity exists between the terminals 2 and
4 on the switch side connector with the switch OFF (belt
unfastened).
If operation is not as specified, replace the switch.
4. 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.

BE0GS±10
I01362
Defogger WireIgnition SwitchDefogger Switch
Defogger Switch
Mirror Assembly

Mirror Defogger
LEXUS navigation
System
Passenger Side
Junction Block

DEF M±Fuse

MIR HTR Fuse

Mirror Defogger Relay
Mirror Assembly

Mirror Defogger
Passenger Cowl Side
Relay Block

Defogger Relay
± BODY ELECTRICALDEFOGGER SYSTEM
BE±107
2408 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
DEFOGGER SYSTEM
LOCATION

BE0GT±03
I04112
6
I04113
I04114
Wire Harness Side
Connector ºAº Connector ºBº
I01200
2 1
35
2 5
1 3
BE±108
± BODY ELECTRICALDEFOGGER SYSTEM
2409 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT DEFOGGER TIMER OPERATION
(a) Connect the positive (+) lead from the voltmeter to termi-
nal 6 of body ECU No.1 connector and negative (±) lead
to body ground.
(b) When the switch is OFF, the voltage should be approx.
12V.
(c) Turn the defogger switch ON and check that the indicator
lights up and that the voltage is less than 1 V.
(d) After 15 minutes, check that the switch is OFF and the
voltage is approx. 12 V.
If operation is not as specified, replace the switch.
2. INSPECT DEFOGGER SWITCH (in PANEL SWITCH)
CIRCUIT
Connector disconnected:
Disconnect the connector from the panel switch and inspect the
connector on wire harness side, as shown in the chart.
Tester connectionConditionSpecified condition
B10 ± GroundConstantContinuity
A1 ± GroundConstantBattery voltage
A2 ± GroundIgnition switch LOCKNo voltage
A2 ± GroundIgnition switch ACC or ONBattery voltage
If the circuit is not as specified, replace the switch.
3. INSPECT DEFOGGER 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.
4. INSPECT DEFOGGER RELAY CIRCUIT
(See page DI±812 and BE±21)

I01200
2 1
35
2 5
1 3
I01291
Tester Probe
Tin FoilHeat Wire
I01292
At Center
I01293
0 Volts
Broken
WireSeveral
Volts
Battery
side Ground sideFoil strip


± BODY ELECTRICALDEFOGGER SYSTEM
BE±109
2410 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
5. INSPECT MIRROR DEFOGGER 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.
6. INSPECT MIRROR DEFOGGER RELAY CIRCUIT
(See page BE±21)
7. INSPECT DEFOGGER WIRE
NOTICE:

When cleaning the glass, use a soft, dry cloth, and wipe the
glass in the direction of the wire. Take care not to damage
the wires.

Do not use detergents or glass cleaners with abrasive in-
gredients.

When measuring voltage, wrap a piece of tin foil around the
tip of the negative probe and press the foil against the wire
with your finger, as shown.
(a) Turn the ignition switch ON.
(b) Turn the defogger switch ON.
(c) Inspect the voltage at the center of each heat wire, as
shown.
VoltageCriteria
Approx. 5VOkay (No break in wire)
Approx. 10V or 0VBroken wire
HINT:
If there is approximately 10 V, the wire is broken between the
center of the wire and the positive (+) end. If there is no voltage,
the wire is broken between the center of the wire and ground.
(d) Place the voltmeter positive (+) lead against the defogger
wire on the battery side.
(e) Place the voltmeter negative (±) lead with the foil strip
against the wire on the ground side.
(f) Slide the positive (+) lead from battery to ground side.
(g) The point where the voltmeter deflects from several V to
zero V is the place where the defogger wire is broken.
HINT:
If the heat wire is not broken, the voltmeter indicates 0 V at the
positive (+) end of the heat wire but gradually increases to about
12 V as the meter probe moves to the other end.

I01294
Repair Point
Broken
Wire
Marking Tape
I01295
I04115
78
I04269
12 13
BE±110
± BODY ELECTRICALDEFOGGER SYSTEM
2411 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
8. IF NECESSARY, REPAIR DEFOGGER WIRE
(a) Clean the broken wire tips with grease, wax and silicone
remover.
(b) Place the masking tape along both sides of the wire for
repair.
(c) Thoroughly mix the repair agent (Dupont paste No.
4817).
(d) Using a fine tip brush, apply a small amount of the agent
to the wire.
(e) After a few minutes, remove the masking tape.
(f) Do not repair the defogger wire for at least 24 hours.
9. w/ Mirror heater (w/o Driving position memory):
INSPECT MIRROR DEFOGGER OPERATION
(a) Connect the positive (+) lead from the battery to terminal
7 and the negative (±) lead to terminal 8.
(b) Check that the mirror becomes warm.
HINT:
It will take a short time for the mirror to become warm.
10. w/ Mirror heater (w/ Driving position memory):
INSPECT MIRROR DEFOGGER OPERATION
(a) Connect the positive (+) lead from the battery to terminal
12 and the negative (±) lead to terminal 13.
(b) Check that the mirror becomes warm.
HINT:
It will take a short time for the mirror to become warm.