battery LEXUS SC400 1991 Service Manual Online

(b) Press the mirror switch and check if the mirrors surfacerepeatedly becomes ºbrightº and ºdarkº.
If operation is not as specified, replace the liquid crystal inner
mirror.
(Circuit)
Disconnect the inner mirror connector and inspect the con-
nector on the wire harness side as shown.
Check forTester connectionConditionSpecified value
Voltage2±GroundConstantBattery voltage
Continuity1 GroundIgnition key setContinuityContinuity1±GroundIgnition key removedNo continuity
If circuit is not as specified, refer to BE±165 wiring diagram
and inspect the circuits connected to other parts.
(Key Unlock Warning Switch)
(See page BE±26)
Troubleshooting
You will find the cause of trouble more easily by properly using the table \
shown below. In this table, the numbers
indicate the order of priority of the cruses of trouble. Check each part in the \
order shown. If necessary, replace
the part.
See pageBE±4,21BE±165BE±26 ±±
TroubleParts
name
DOME FuseLiquid Crystal Inner MirrorKey Unlock Warning SwitchWire Harness
Liquid Crystal Inner Mirror does not operate.1234
BE±166±
BODY ELECTRICAL SYSTEM Liquid Crystal Inner Mirror System
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Parts Inspection
(Tension Reducer Solenoid)
REMOVAL AND INSTALLATION OF
TENSION REDUCER SOLENOID
(See page BO±71)
INSPECTION OF TENSION REDUCER
SOLENOID
INSPECT TENSION REDUCER SOLENOID
(Operation)
(a) Connect the positive (+) lead from the battery to terminal
2, and negative (±) lead to terminal 1.
(b) Pull the belt upward and check that the belt is slowly retracted 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.
(Circuit)
Disconnect the tension reducer solenoid connector and in-
spect the connector on wire harness side as shown.
Check forTester connectionConditionSpecified value
Voltage2±GroundIgnition switchONBattery voltagegg
positionACC or LOCKNo voltage
Continuity1±GroundBuckle switch positionON (belt fastened)Continuityy
OFF (belt unfastened)No continuity
If the circuit is specified, replace the front seat outer belt as-
sembly.
If the circuit is not as specified, refer to BE±167 wiring dia-
gram, and inspect the circuits connected to other parts.
BE±168
±
BODY ELECTRICAL SYSTEM Electric Tension Reducer System
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(Buckle Switch)
REMOVAL AND INSTALLATION OF
BUCKLE SWITCH
1. REMOVE BUCKLE SWITCH(a) Remove the driver or front passenger's seat.
(b) Disconnect buckle switch connector.
(c) Remove seat belt inner with buckle switch.
2. INSTALL BUCKLE SWITCH For installation follow the removal procedure in reverse.
INSPECTION OF BUCKLE SWITCH
INSPECT BUCKLE SWITCH(Switch Continuity)
(a) Check that there is continuity between terminals on theswitch side connector with the switch ON (belt
fastened).
(b) Check that there is no continuity between terminals on the switch side connector with the switch OFF (belt
unfastened).
If operation is not as specified, replace the seat belt inner.
(Switch Circuit)
Disconnect the connector from switch and inspect the con-
nector on wire harness side as shown.
Check forTester connectionConditionSpecified value
Voltage2±GroundIgnition switch posi-ONBattery voltagegg
tionACC or LOCKNo voltage
Continuity1±GroundConstantContinuity
If the circuit is not as specified, refer to BE±167 wiring dia-
gram, and inspect the circuits connected to other parts.
±
BODY ELECTRICAL SYSTEM Electric Tension Reducer SystemBE±169
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Wiring and Connector Diagrams
Parts Inspection
(Defogger Switch)
REMOVAL AND INSTALLATION OF AIR
CONDITIONER CONTROL PANEL
ASSEMBLY
(See Instrument Panel on page BO±111)
INSPECTION OF DEFOGGER SWITCH
INSPECT SWITCH OPERATION
(a) Connect the positive (+) lead from the battery to terminal
A6 and negative (±) lead to terminal A7.
(b) Connect the positive (+) lead from the battery to terminal
B10 through a 1.4 W test bulb.
BE±172
±
BODY ELECTRICAL SYSTEM Defogger System
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(c) Turn the defogger switch ON and check that the testbulb and indicator light turn ON, then turn OFF after
about 15 minutes.
If operation is not as specified, replace the air conditioner
control panel assembly.
(Defogger Relay)
INSPECTION OF DEFOGGER RELAY
INSPECT RELAY CONTINUITY AND OPERATION
Terminal
ConditionConstant
Apple battery voltage to terminals 1 and 3.
If continuity is not as specified, replace the relay.
(Defogger Wires)
INSPECTION AND REPAIR OF
DEFOGGER WIRES
1. INSPECT DEFOGGER WIRES
NOTICE:
w VWhen 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.
w VDo not use detergents or glass cleaners with abrasive
ingredients.
w VWhen measuring voltage, wind a piece of tin foil around
the top 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. 5 VOkay (No break in wire)
Approx. 10 V or 0 VBroken wire
HINT: If there is approximately 10 volts, the wire is broken be-
tween 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.
±
BODY ELECTRICAL SYSTEM Defogger SystemBE±173
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INSPECTION OF MIRROR DEFOGGER
INSPECT MIRROR DEFOGGER(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.
If the mirror does not become warm, replace the mirror as-
sembly.
Troubleshooting
You will find the cause of trouble more easily using the table shown below. In this table, the number indicate
the order priority of the causes in trouble. Check each part in the order s\
hown. If necessary, replace the parts.
See pageBE±4 ,20BE±4,20BE±4,22BE±172BE±173 ±±BE±173 ±±BE±174
TroubleParts
name
HEATER FuseMIR±HTR FuseDEFOG FuseDefogger SwitchDefogger RelayWire HarnessDefogger WiresCKE CoilMirror Defogger
All defogger systems do not operate.11234
Rear window defogger does not operate.312
Mirror Defogger does not operate.132
±
BODY ELECTRICAL SYSTEM Defogger SystemBE±175
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Parts Inspection
(Power Window Main Relay)
INSPECTION OF POWER WINDOW MAIN
RELAY
(See Power Window Main Relay on page BE±152)
(Sliding Roof Switch)
REMOVAL AND INSTALLATION OF
SLIDING ROOF SWITCH
(See Sliding Roof on page BO±85)
INSPECTION OF SLIDING ROOF SWITCH
INSPECT SWITCH CONTINUITY
Terminal
Switch position
SLIDE
TILT OFF
OPEN
CLOSE
OFFUP
DOWN
If continuity is not as specified, replace the switch.
(Sliding Roof Motor)
REMOVAL AND INSTALLATION OF
MOTOR
(See Sliding Roof on page
BO±85)
INSPECTION OF MOTOR
INSPECT MOTOR OPERATION
(a) Disconnect the connector which has 3 terminals andinspect on the clamped connector side.
(b) Connect the positive (+) lead from the battery to terminal
1 and negative (±) lead to terminal 3 and check that the
motor turns clockwise.
(c) Connect the positive (+) lead from the battery to terminal
3 and negative (±) lead to terminal 1 and check that the
motor turns counterclockwise.
If operation is not as specified, replace the motor.
(d) Connect the connector.
±
BODY ELECTRICAL SYSTEM Sliding Roof SysytemBE±179
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(Sliding Roof Control Relay)
REMOVAL AND INSTALLATION OF
SLIDING ROOF CONTROL RELAY
(See Sliding Roof on page BO±85)
INSPECTION OF SLIDING ROOF
CONTROL RELAY
INSPECT CONTROL RELAY CIRCUIT
Disconnect the connector from the relay and inspect the con-
nector on the wire harness side as shown in the chart.
Check forTest connectionConditionSpecified value
ContinuityA2 ± GroundSliding roof control OFF or UPNo continuityyg
switch position (TILT)DOWNContinuity
A6 ± GroundSliding roof control OFF or DOWNNo continuityg
switch position (TILT)UPContinuity
A7 ± GroundSliding roof control OFF or OPENNo continuityg
switch position (SLIDE)CLOSEContinuity
A8 ± GroundSliding roof control OFF or CLOSENo continuityg
switch position (SLIDE)OPENContinuity
B1 ± GroundConstantNo continuity
B1 ± B3ConstantContinuity
B2 ± GroundNo. 1 limit switch
p
osition
OFF (Sliding roof tilt up or
approx. 200 mm (7.87 in.)
opened)No continuity
positionON (Except for conditions
mentioned above)Continuity
B3 ± GroundConstantNo continuity
B4 ± GroundConstantContinuity
B5 ± GroundConstantContinuity
B6 ± GroundNo. 2 limit switch OFF (Sliding roof closed)No continuity
positionON (Sliding roof opened)Continuity
VoltageA1 ± GroundConstantBattery voltageg
A3 ± GroundIgnition switch positionLOCK or ACC ( * )No voltageg
ONBattery voltage
(*) Except within 60 seconds after turning the ignition key to the OFF\
position and both the driver's door and
the passenger's door are closed. If circuit is as specified, replace the relay.
BE±180
±
BODY ELECTRICAL SYSTEM Sliding Roof System
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Parts Inspection
(Mirror Switch)
REMOVAL AND INSTALLATION OF
MIRROR SWITCH
(See Instrument Panel on page BO±33)
INSPECTION OF MIRROR SWITCH
INSPECT SWITCH CONTINUITY

Rear View adjustment switch
Left/Right Select
Switch Position
Terminal
Switch Position OFF
UP
DOWN LEFT
RIGHT LEFT SIDE RIGHT SIDE


Left/Right select switch
If continuity is not as specified, replace the switch.
(Mirror Motor)
REMOVAL AND INSTALLATION OF
OUTSIDE MIRROR ASSEMBLY
(See Outside Rear View Mirror on page BO±42)
INSPECTION OF MIRROR MOTOR
1. INSPECT MIRROR MOTOR OPERATION
(a) Connect the positive (+) lead from the battery to terminal
1 and negative (±) lead to terminal 2 check that the
mirror turns to left side.
(b) Reverse the polarity, check that the mirror turns to right side.
(c) Connect the positive (+) lead from the battery to terminal
3 and negative (±) lead to terminal 2 check that the
mirror turns upward.
(d) Re ve rse th e po la rity, ch e ck th a t th e mirro r tu rn s
downward.
BE±186
±
BODY ELECTRICAL SYSTEM Power Mirror Control System
Terminal
Switch Position
OFF
LEFT
RIGHT
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2. INSPECT MIRROR POSITION SENSORSHINT: Strip off the vinyl tape of the connector and remove ter-
minals 1, 2, 3, 5 and 9 from the connector housing.
(a) Connect a series of three 1.5 volt dry cell batteries.
(b) Connect the positive (+) lead from the dry cell batteriesto terminal 5 and the negative (±) lead to terminal 9.
(c) Connect the positive (+) lead from the voltmeter to
terminal 6 and the negative (±) lead to terminal 9.
(d) Apply battery voltage to terminals 2 and 3, check that the voltage gradually changes according to the table
below while the mirror moves between the uppermost
position and lowermost position.
Mirror
positionLowermostUppermost
Voltage2.8 ± 5.0Changes
gradually0 ± 0.9
If voltage value is not as specified, replace the motor assem-
bly.
(e) Disconnect the four leads of the battery and voltmeter.
(f) Connect the positive (+) lead from the voltmeter to terminal 4 and the negative (±) lead to terminal 9.
(g) Apply battery voltage to terminals 1 and 2n inspect that the voltage gradually changes according to the table
below while the mirror moves between the leftmost
position and rightmost position.
Mirror
PositionLeftmostRightmost
Voltage
Left
Mirror2.8 ± 5.0Changes
gradually0 ± 0.9
VoltageRight
Mirror0 ± 0.9Changes
gradually2.8 ± 5.0
If voltage value is not as specified, replace the motor assem-
bly.
(Mirror ECU)
REMOVAL AND INSTALLATION OF
MIRROR ECU
REMOVAL AND INSTALL MIRROR ECU (a) Remove the No. 1 under cover .(See page BO±112)
(b) Re mo ve th e two scre ws an d disc onnect the two
connectors and then pull out the ECU.
(c) For installation, follow the removal procedure in reverse.
±
BODY ELECTRICAL SYSTEM Power Mirror Control SystemBE±187
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