1991 LEXUS SC400 oil temperature

DESCRIPTION
The combination meter has various meters and gauges which show the vehicle'\
s condition, warning lights which
monitor abnormalities in the vehicle and inform the driver, indicator lights which inform the driver of the condition
of each part of vehicle, and a function for illumination and brightness ad\
justment of meters and gauges.
The component parts of this system and their functions are described in \
the following table.
Parts NameFunction
SpeedometerThe speedometer needle moves in accordance with signals from the speed s\
ensor to
indicate the vehicle's speed.
TachometerThe tachometer needle moves in accordance with signals from the igniter \
to indicate the
engine's speed.
Water Temperatrue
GaugeThe water temperature gauge's needle moves in accordance with signals from the send-
er gauge and indicates the temperature of the engine coolant.
Fuel GaugeThe fuel gauge needle moves in accordance with signals from the sender g\
auge, indicat-
ing the amount of fuel remaining in the fuel tank.
OdometerThe odometer counts the total distance traveled by the vehicle in accord\
ance with pulse
signals from the speed sensor.
Twin Trip Switch
The twin trip meter counts the distance traveled by the vehicle in accor\
dance with pulse
signals from the speed sensor. It can be reset using a switch and can be used to switch
between trip meters A and B.
Circuit Plate
This plate contains the circuitry for each meter and gauge and for each \
warning light and
indicator light, as well as an internal engine oil level warning drive c\
ircuit, drive circuits for
the odometer and trip meter and brightness adjustment circuitry for each\
indicator.
Speed SensorMounted in the transmission, this sensor outputs pulse signals to the co\
mbination meter
in accordance with the speed of the output shaft.
Twin Trip SwitchOperation of this switch switches between the A and B trip meters and se\
nds reset sig-
nals to the combination meter.
Water
Temperature Sender
GaugeThis sender converts engine coolant temperatures to a resistance value i\
n signal form to
the combination meter.
Fuel Sender GaugeThis sender converts the level of fuel remaining in fuel tank to resista\
nce value and
sends the resistance value in signal form to combination meter.
Rheostat Light
Control VolumeIn order to adjust the degree of illumination of the combination meter, the resistance val-
ue of the built±in variable resistor is sent to the combination meter\
and rheostat light
control.
Fuel Level Warning
SwitchWhen the level of fuel remaining falls below a predetermined level, cont\
inuity is estab-
lished with this switch, which is built into the fuel sender gauge, caus\
ing a warning light
to light up.
Low Oil Pressure
Warning SwitchThis switch is mounted on the engine block. Continuity is established in\
this switch when
the oil pressure is low, causing a warning light to light up.
Integration Relay (Seat
Belt Warning Relay)
This relay receives current from fuse GAUGE and DOME and is connected to\
each
buckle switch, door courtesy switch, key unlock warning switch and warni\
ng light. As
part of the seat belt warning system, it sounds a chime and lights a war\
ning light when
seat belts are unfastened. As part of the key unlock warning system, it \
sounds a chime
when the set conditions are fulfilled.
Light Failure SensorThis sensor senses when a bulb in rear combination light is burnt out an\
d lights up a
warning light.
BE±96±
BODY ELECTRICAL SYSTEM Combination Meter
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ConnectionCheck forTester connectionConditionSpecified value
Turn signalHazard warning switch ONBattery positiveTurn signal
SW andB 16 Ground
Hazard warning switch ONBattery ositive
voltage e 0V
HazardB±16±Ground
IG SW ON and turn signal SW ºLeftºBattery positive
Warning
Si hVoltage
IG SW ON and turn signal SW ºLeftºBattery ositive
voltage e 0V
SwitchVoltage
Hazard warning switch ONBattery positive
B 17 Ground
Hazard warning switch ONBattery ositive
voltage e 0VB±17±Ground
IG SW ON and turn signal SW ºRightºBattery positiveIG SW ON and turn signal SW ºRightºBattery ositive
voltage e 0V
HeadlightLi ht t l SWDimmer SW ºHIº orBattery positiveHeadlight
VoltageB7±GroundLight control SW
ºHEADº
Dimmer SW HI or
ºFlashº
Battery ositive
voltageVoltageB7±GroundºHEADºDimmer SW ºLOºNo voltage
ContinuityB6±GroundLight control SW
º
HEADº
Dimmer SW ºHIº or
ºFlashºContinuityContinuityB6 GroundºHEADºDimmer SW ºLOºNo continuity
IgniterVoltageA9±GroundEngine RunningVoltage
fluctuates
ECT patternVoltageB4 GroundIG SW ON and ECT patternPWRBattery positive voltageECT attern
Select switchVoltageB4±GroundIG SW ON and ECT attern
select SW positionNORMNo voltage
Engine oilOil temperature below approx. 55 5C (131 5F)Continuityg
Level warn-
ing Switch
ContinuityB8±Ground
Oil temperature
above approx. 55 5CON (float up)ContinuitygContinuityB8 Groundabove a rox. 55 C
(131 5F) and SW
positionOFF (float off)No continuity
GAUGE fuseVoltageA1 GroundIgnition switchONBattery positive voltageVoltageA1±GroundIgnition switch
positionLOCK, ACC, STARTNo voltage
Neutral StartVoltageA12±GroundIgnition switch
position
START (ºPº or ºNº
range)Battery positive voltage
switch
VoltageA12 GroundpositionLOCK, ACC, ONNo voltage
ECU±BVoltageC11 GroundIgnition switchONBattery positive voltage
FuseVoltageC11±GroundIgnition switch
positionLOCK, ACC, STARTNo voltage
Rheostat
Li ht t l
ON (Rheostat knob
t d itiBtt ltLight control
VolumeLight control SWturned any position
except fully clock-
Battery voltage or
5V or moreVolume
VoltageA2±Ground
g
HEAD or TAIL and
rheostat volume
except fully clock-
wise)5V or more
VoltageA2 Groundrheostat volume
knob positionOFF (Rheostat knob)
turned fully clockNo voltageknob ositionturned fully clock-
wise)No voltage
GroundA8±GroundConstantContinuity
ContinuityA10±GroundConstantContinuityContinuityA22±GroundConstantContinuity
A23±GroundConstantContinuity
*1 Jack up the vehicle.*2 Shift lever position is ºPº range.
If circuit is not as specified, refer to BE±100 wiring diagrams
and inspect the circuits connected to other parts.
BE±108
±
BODY ELECTRICAL SYSTEM Combination Meter
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2. APPLY HIGH TEMPERATURE GREASE TO ADJUSTER
3. CONNECT PARKING BRAKE CABLE TO PARKINGBRAKE LEVER
(a) Install the shoe hold±down springs, cups and pins.
(b) Connect the parking brake cable to the parking brake shoe
lever of the rear shoe.
4. INSTALL REAR SHOE Slide in the rear shoe between the shoe hold±down spring
cup and the backing plate.
NOTICE: Do not allow oil or grease to get on the rubbing face.
5. INSTALL TENSION SPRING, FRONT SHOE ANDADJUSTER
(a) Install the tension spring on the rear shoe.
(b) Install the front shoe on the tension spring.
(c) Install the adjuster between the front and rear shoes.
(d) Slide in the front shoe between the shoe hold±down spring
cup and the backing plate.
BR±48
±
BRAKE SYSTEM REAR BRAKE (Parking Brake)
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SERVICE SPECIFICATIONS
SERVICE DATA
ThermostatValve opening temperature80±845C176±183 5F
Valve liftat 95 5C (203 5F) 10 mm0.39 in.
Radiator capRelief valve opening pressureSTD74±103 kPa
(0.75±1.05 kgf/cm, 10.7±14.9 psi)
Limit 59 kPa 0.6 kgf/cm 8.5 psi
On±vehicle
itifh
Oil pressure1,177±2,452 kPa
inspection for hy-
draulic cooling(12±25 kgf/cm, 171±356 psi)draulic cooling
fan
fan
Hydraulic pumpSpool valve45.8 mm1.803 in.
Rotor side clearanceSTD Drive rotor 0.02 mm0.0008 in.
Driven rotor 0.03 mm0.0012 in.
Limit Drive rotor 0.03 mm0.0012 in.
Driven rotor 0.04 mm0.0016 in.
Rotor body clearanceSTD 0.05±0.09 mm0.0020±0.0035 in.
Limit 0.10 mm0.0039 in.
Rotor tip clearanceSTD 0.02 mm0.0008 in.
Limit 0.03 mm0.0012 in.
Drive shaft bushing inside diameter17.00±17.05 mm0.6693±0.6713 in.
Drive shaft diameter16.97±16.98 mm0.6681±0.6685 in.
Drive shaft oil clearanceSTD 0.02±0.08 mm0.0008±0.0031 in.
Limit 0.08 mm0.0031 in.
Drive shaft preload (rotating torque)0.3 N Vm 3.0 kgf Vcm 2.6 in. Vlbf
Solenoid valve resistanceat cold 7.5±8.5

Hydraulic motorRotor side clearanceSTD0.01±0.04 mm0.0004±0.0016 in.
Limit 0.05 mm0.0020 mm
Drive shaft hole inside diameter14.000±14.011 mm0.5512±0.5516 in.
Drive shaft diameter13.973±13.984 mm0.5501±0.5506 in.
Drive shaft oil clearanceSTD 0.016±0.038 mm0.0006±0.0015 in.
Limit 0.04 mm0.0031 in.
Drive shaft preload (rotating torque)0.3 NVm 3.0 kgf Vcm 2.6 in. Vlbf
Water temp. Resistanceat 80 5C (176 5F)1.48±1.58 k

sensor
CO±64±
COOLIING SYSTEM Service Specifications
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TORQUE SPECIFICATIONS
Part tightenedNVmkgf Vcmft Vlbf
Engine drain plug X Cylinder block1818013
Coolant filler plug X Water inlet housing44450 33
Water pump X Cylinder block18185 13
Water inlet housing X Water pump18185 13
Water inlet X Water inlet housing18185 13
Radiator fan shroud X Radiator4.950 43 in. Vlbf
Radiator X Body12120 9
Cooling fan reservoir tank X Radiator fan shroud4.950 43 in. Vlbf
Cooling fan inlet pipe X Radiator fan shroud4.950 43 in. Vlbf
Cooling fan pressure hose X Hydraulic motor64650 47
Radiator reservoir tank X Upper radiator support4.950 43 in. Vlbf
Radiator reservoir tank X Radiator reservoir tank support4.950 43 in. Vlbf
Hydraulic pump rear housing X End plug (for spool valve)19200 14
Hydraulic pump front housing X Rear housing21210 15
Hydraulic pump pulley X Drive shaft59600 43
Solenoid valve X Hydraulic pump rear housing39400 28
Hydraulic pump suction port union X Rear housing13135 10
 Hydraulic pump X Cylinder block 12 mm head 16 160 12
  14 mm head 20 310 22
\
 \
Cooling fan pressure hose X Hydraulic pump 64 650 47
\
 \
RH No.2 timing belt cover X Cylinder block 16 160 12
\
 \
Drive belt idler pulley X Hydraulic pump 37 380 27
\
 \
A/C compressor X Hydraulic pump 49 500 36
\
 \
A/C compressor X Cylinder block 49 500 36\
 \
A/C compressor stay X Oil filter bracket 29 300 22\
 \
Hydraulic motor cover X Motor housing 28 290 21\
 
\

\
Hydraulic motor X Radiator fan shroud
 

4.9
 

50
 

43 in.
Vlbf
\
 \
Cooling fan X Hydraulic motor 15 150 11
\
 \
Cooling fan oil cooler X Body 18 180 13
\
 \
Water temperature sensor X Radiator 7.4 75 65 in. Vlbf
±
COOLIING SYSTEM Service SpecificationsCO±65
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CHECK AND REPLACEMENT OF
ENGINE COOLANT
1. CHECK ENGINE COOLANT LEVEL AT RESERVOIR TANK
The coolant level should be between the ºLOWº and ºFULLº
lines at low temperature.
If low, check for leaks and add coolant up to the ºFULLº line.
2. CHECK ENGINE COOLANT QUALITY There should be no excessive deposits of rust or scales
around the radiator cap or radiator filler hole, and the coolant
should be free from oil.
If excessively dirty, replace the coolant
3. REPLACE ENGINE COOLANT (a) Remove the radiator cap.
CAUTION: To avoid the danger of being burned, do not
remove it while the engine and radiator are still hot, as
fluid and steam can be blown out under pressure.
(b) Drain the coolant from the radiator drain cock andengine drain plug.
(c) Close the drain cock and plug.
Torque (Engine drain plug):
29 NVm (300 kgf Vcm, 22 ft Vlbf)
(d) Fill the system with coolant.
w Use a good brand of ethylene±glycol base coolant,
mixed according to the manufacturer's direction.
w Using coolant which includes more than 50 %
ethylene±glycol (but not more than 70%) is
recommended.
NOTICE:
w Do not use alcohol type coolant.
w The coolant should be mixed with demineralized water or
distilled water.
Coolant capacity (w/ Heater): M/T 8.5 liters (9.0 US qts, 7.5 Imp. qts)
A/T 8.4 liters (8.9 US qts, 7.4 Imp. qts)
(e) Install the radiator cap.
(f) Start the engine and check for leaks.
(g) Recheck the coolant level and refill as necessary.
±
COOLING SYSTEM Check and Replacement of Engine CoolantCO±5
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CHECK AND REPLACEMENT OF
ENGINE COOLANT
1. CHECK ENGINE COOLANT LEVEL AT RESERVE TANKThe coolant level should be above the ºCOLD LEVELº at nor-
mal temperature (20 5C (68 5F)).
If low, check for leaks and add coolant up to the ºCOLD LEV-
ELº.
2. CHECK ENGINE COOLANT QUALITY There should not be any excessive deposits of rust or scales
around the radiator cap or reservoir tank filler hole, and the
coolant should be free from oil.
If excessively dirty, clean the coolant passages and replace
the coolant.
3. REPLACE ENGINE COOLANT (a) Remove the radiator cap from the reservoir tank.
CAUTION: To avoid the danger of being burned, do not
remove the cap while the engine and radiator are still hot,
as fluid and steam can be blown out under pressure.
(b) Remove the filler plug from the water inlet housing.
(c) Loosen the three drain plugs on the radiator and
cylinder block, drain the coolant from the radiator and
engine.
(d) Clean the coolant passages.
(e) Close the three drain plugs.
Torque (Engine drain plug):
18 NVm (180 kgf Vcm, 13 ft Vlbf)
CO±6±
COOLIING SYSTEM Check and Replacement of Engine Coolant
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(3) Upper radiator hose or radiator
(4) Reservoir hose to radiator
5. INSTALL BATTERY
6. FILL ENGINE WITH COOLANT (See page CO±5)
Capacity (w/ Heater):
M/T 8.5 liters (9.0 US qts, 7.5 Imp. qts)
A/T 8.4 liters (8.9 US qts, 7.4 Imp. qts)
7. (A/T)
CHECK AUTOMATIC TRANSMISSION FLUID LEVEL (See pageMA±11 )
NOTICE: Do not overfill.
8. START ENGINE AND CHECK FOR LEAKS
9. INSTALL ENGINE UNDER COVER
SERVICE SPECIFICATIONS
SERVICE DATA
ThermostatValve opening temperature80±84 5c176±183 5F
Valve liftat 95 5C (203 5F) 8.5 mm0.335 in.
Radiator capRelief valve opening pressureSTD74±103 kPa
(0 75 1 05 k f/ 10 7 14 9 i)(0.75±1.05 kgf/cm, 10.7±14.9 psi)
Limit59 kPa0.6 kgf/cm28.5 psi
TORQUE SPECIFICATIONS
Part tightenedN
mkgf
cmft
lbf
Engine drain plug X Cylinder block2930022
Water pump X Cylinder block2121015
Water pump X Water by±pass pipe2121015
Water by±pass outlet X Cylinder head 8.89078 in.
lbf
Water inlet X Water pump 8.89078 in.
lbf
Oil cooler X Radiator lower tank (A/T) 8.38574 in.
lbf
Oil cooler X Pipe (A/T)1515011
Radiator fan shroud X Radiator 4.95043 in.
lbf
Radiator X Body121209
±
COOLING SYSTEM Radiator, Service SpecificationsCO±21
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