sensor LEXUS SC300 1991 Service Repair Manual

(Water Temperature Sensor)
COMPONENTS FOR REMOVAL AND
INSTALLATION
INSPECTION OF WATER TEMPERATURE
SENSOR
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Work must be started after 20 seconds or
longer from the time the ignition switch is turned to the
ºLOCKº position and the negative (±) terminal cable is
disconnected from the battery.
2. REMOVE ENGINE UNDER COVER
3. DRAIN ENGINE COOLANT (See page CO±6)
4. REMOVE WATER TEMPERATURE SENSOR (a) Disconnect the water temperature sensor connector.
(b) Remove the water temperature sensor from left side ofthe radiator lower tank.
(c) Remove the O±ring from the water temperature sensor.
CO±62
±
COOLIING SYSTEM Electronically Controlled Hydraulic
Cooling Fan (Electronic Control Parts)
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5. INSPECT WATER TEMPERATURE SENSORUsing an ohmmeter, measure the resistance between the ter-
minals.
Resistance: 1.48±1.58 k
at 80 5C (176 5F)
If the resistance is not as specified, replace the sensor.
6. REINSTALL WATER TEMPERATURE SENSOR (a) Install a new O±ring to the water temperature sensor.
(b) Apply soapy water to the O±ring.
(c) Install the water temperature sensor to the radiator.
Torque: 7.4 N Vm (75 kgf Vcm, 65 in. Vlbf)
(d) Connect the water temperature sensor connector.
7. REFILL WITH ENGINE COOLANT (See page CO±7)
8. REINSTALL ENGINE UNDER COVER
9. RECONNECT CABLE FROM NEGATIVE TERMINAL OF BATTERY
(A/C High±Pressure Switch)
INSPECTION OF A/C HIGH±PRESSURE
SWITCH
1. DISCONNECT HIGH±PRESSURE SWITCH CONNECTOR
2. INSTALL MANIFOLD GAUGE SET (See AC section)
3. INSPECT HIGH±PRESSURE SWITCH(a) Wh e n th e A/C switch is OFF, ch e ck th a t th e re iscontinuity between terminals 2 and 3. (When the
pressure is 1,226 kPa (12.5 kgf/cm
2, 178 psi) or lower.)
(b) When the A/C switch and blower switch are ON, check
that there is no continuity between terminals 2 and 3.
(When the pressure is 1,520 kPa (15.5 kgf/cm
2, 220 psi)
or higher.)
If continuity is not as specified, replace the switch.
4. REMOVE MANIFOLD GAUGE SET
5. RECONNECT HIGH±PRESSURE SWITCH CONNECTOR
(Solenoid Valve)
(See page CO±36)
±
COOLIING SYSTEM Electronically Controlled Hydraulic
Cooling Fan (Electronic Control Parts)CO±63
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SERVICE SPECIFICATIONS
SPECIFICATIONS
VSV (For EVAP) Resistance30±34

VSV (For EGR)Resistance33±39

TORQUE SPECIFICATIONS
Part tightenedN mkgf cmftVlbf
VSV for EGR X Intake manifold18185 13
EGR valve X Intake manifold18185 13
EGR valve X EGR Pipe64650 47
Catalytic converter (Front) X Exhaust manifold62630 46
Catalytic converter (Front) X Front Exhaust pipe43440 32
Front exhaust pipe X Center exhaust pipe43440 32
Sub±oxygen sensor X Front exhaust pipe1818013
EC±20±
EMISSION CONTROL SYSTEMS Service Specifications
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(Sub±Catalytic Converter (USA Spec.
only)
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Work must be started after, approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
2. DISCONNECT SUB±OXYGEN SENSOR CONNECTORS Disconnect the grommet from the floor, and disconnect the
sub±oxygen sensor from the front exhaust pipe.
3. REMOVE FRONT EXHAUST PIPE (SUB±CATALYTIC CONVERTER)
(a) Remove the four bolts holding the front exhaust pipe tothe transmission.
(b) Remove the two bolts and nuts holding the front exhaust
pipe to the center exhaust pipe.
(c) Remove the four bolts and nuts holding the front pipe to the catalytic converter, and remove the pipe support
bracket, front pipe and three gaskets.
4. REINSTALL FRONT EXHAUST PIPE (SUB±CATALYTIC CONVERTER)
(a) Temporarily install the pipe support bracket to thetransmission with the four bolts.
(b) Install three new gaskets, the front exhaust pipe and pipe support bracket with the six bolts and new nuts.
Torque: 43 N Vm (440 kgf Vcm, 32 ft Vlbf)
(c) Tighten the four bolts holding the pipe support bracket
to the transmission.
Torque: 43 N Vm (440 kgf Vcm, 32 ft Vlbf)
5. RECONNECT SUB±OXYGEN SENSOR CONNECTORS
(a) Install the two sub±oxygen sensors to the front exhaustpipe.
Torque: 44 N Vm (450 kgf Vcm, 33 ft Vlbf)
HINT:
w Before installing the s ub±oxygen sensor, twist the
sensor wire counterclockwise 3 \frb\1/2\fre turns.
w After installing the sub±oxygen sensor, check that the
sensor wire is not twisted. If it is twisted, remove the
sub±oxygen sensor and reinstall it.
(b) Install the two wire grommets to the floor.
6. RECONNECT CABLE TO NEGATIVE TERMINAL OF
BATTERY
±
EMISSION CONTROL SYSTEMS Three±Way Catalyst (TWC) SystemEC±29
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SERVICE SPECIFICATIONS
SERVICE DATA
VSVResistance30±34

for EVAP
VSVResistance33±39

for EGR
EGR valveResistance19.9±23.4

(CALIF. only)
TORQUE SPECIFICATIONS
Part tightenedNVmkgf Vcmft Vlbf
VSV for EGR X Air intake chamber (Exc. USA Spec.)1818513
EGR valve X Air intake chamber18185 13
Catalytic converter (Main) X Exhaust manifold62630 46
Catalytic converter (Main) X Front exhaust pipe43440 32
Front exhaust pipe support bracket X Transmission43440 32
Front exhaust pipe X Center exhaust pipe43440 32
Main oxygen sensor X Front exhaust pipe4445033
EC±30±
EMISSION CONTROL SYSTEMS Servuce Specifications
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INSPECTION OF EGR VALVE
1. REMOVE EGR VALVE(a) Disconnect the following hoses:(1) Vacuum hose from EGR vacuum modulator
(2) Pressure hose from EGR vacuum modulator(USA Spec.)
(b) Disconnect the EGR Gas Temp. Sensor connector
(c) Loosen the nut for EGR pipe.
(d) Remove the two nuts, EGR valve and gasket.
2. INSPECT EGR VALVE Check for sticking and heavy carbon deposits.
If a problem is found, replace the EGR valve assembly.
3. REINSTALL EGR VALVE (a) Place a new gasket on the intake manifold.
(b) Install the EGR valve with the two nuts.
Torque: 18 N Vm (185 kgf Vcm, 13 ft Vlbf)
(c) Torque the nut for EGR pipe.
Torque: 64 N Vm (650 kgf Vcm, 47 ft Vlbf)
±
EMISSION CONTROL SYSTEMS Exhaust Gas Recirculation (EGR) SystemEC±15
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(d) Connect the following hoses:(1) Vacuum hose from EGR vacuum modulator
(2) Pressure hose from EGR vacuum modulator(USA Spec.)
(e) Connect the EGR Gas Temp. Sensor connector.
EC±16
±
EMISSION CONTROL SYSTEMS Exhaust Gas Recirculation (EGR) System
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(Rear Catalytic Converter)
1. (USA Spec.)REMOVE SUB±OXYGEN SENSOR
Remove the two nuts and sub±oxygen sensor from the front
exhaust pipe.
2. REMOVE REAR CATALYTIC CONVERTER (FRONT EXHAUST PIPE)
(a) Remove the two bolts and nuts holding the front exhaust
pipe to the center exhaust pipe.
(b) Remove the two bolts and nuts holding the front exhaust
pipe to the front catalytic converter, and remove the front
exhaust pipe and two gaskets.
3. REINSTALL REAR CATALYTIC CONVERTER (FRONT EXHAUST PIPE)
Install the two new gaskets, the front exhaust pipe with the
four bolts and new nuts.
Torque: 43 N Vm (440 kgf Vcm, 32 ft Vlbf)
4. (USA Spec.)
REINSTALL SUB±OXYGEN SENSOR
Install the new gasket, the sub±oxygen sensor to the front ex-
haust pipe with the two nuts.
Torque: 18 N Vm (180 kgf Vcm, 13 ft Vlbf)
±
EMISSION CONTROL SYSTEMS Three±way Catalyst (TWC) SystemEC±19
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Front water bypass joint x Cylinder head  18 185 13
 Intake manifold x Cylinder head1818513
Delivery pipe x Intake manifold1818513 
Fuel return pipe x Fuel pressure regulator
  
35
 
360
 
26 Fuel inlet hose x Delivery pipe  39 400 29  for SST 33 340 24 Cold start injector x Air intake chamber  7.8 80 69 in.Vlbf Air intake chamber x Intake manifold  18 185 13 EGR pipe x Air intake chamber  18 185 13
 EGR pipe x RH cylinder head  18 185 13
 Cold start injector tube x Air intake chamber  15 150 11
 Union (for brake booster) x Air intake chamber  29 300 22
 Throttle body x Air intake chamber  18 185 13
 IAC valve x Air intake chamber  18 185 13
 EGR valve adaptor x Air intake chamber  18 185 13
 EGR valve x EGR valve adaptor  18 185 13
Timing belt rear plate x Cylinder head7.88069 in. Vlbf 
Water outlet housing x Water pump
  
18
 
185
 
13 Main bearing stud bolt x Cylinder block  15 150 11 Main bearing cap x Cylinder block for nut (1st) 27 275 20  (2nd) Turn 90 5  
  for bolt 49 500 36 Connecting rod cap x Connecting rod 1st 25 250 18
  2nd Turn 905  
 Rear oil seal retainer x Cylinder block  7.8 80 69 in.Vlbf
 Water seal plate x Cylinder block  14 145 10
 Generator bracket x Cylinder block  18 185 13
 Oil pump x Cylinder block 12 mm head 16 160 12
  14 mm head 30 310 22
 No.1 oil pan x Cylinder block 10 mm head 7.8 80 69 in. Vlbf
12 mm head1818513 
No.1 oil pan x Oil pump
  
7.8
 
80
 
69 in. Vlbf No.1 oil pan x Rear oil seal retainer  7.8 80 69 in. Vlbf Oil strainer x Cylinder block  7.8 80 69 in. Vlbf Oil strainer x Oil pump  7.8 80 69 in. Vlbf Oil pan baffle plate x No.1 oil pan  7.8 80 69 in. Vlbf No.1 oil pan x No.2 oil pan  7.8 80 69 in. Vlbf
 Water pump x Cylinder block  18 185 13
 Water bypass pipe x Cylinder Block  18 185 13
 Knock sensor x Cylinder block  44 450 33
 Starter x Cylinder block  39 400 29
 Engine mounting bracket x Cylinder block  37 380 27
 Drive plate x Crankshaft  98 1,000 72
 Transmission x Cylinder block  57 580 42
 Transmission x No.1 oil pan  39 400 29
Drive plate x Torque converter3334025 Transmission oil cooler pipe x Transmission for union nut 34 350 25 Rear engine mounting member x Body  25 250 19\
 \
Rear engine mounting member x Rear engine mounting insulator1313510
EG±210±
1UZ ± FE ENGINE ENGINE MECHANICAL
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\
 \

Front suspension crossmember x Engine mounting insulator  59 600 43
\
 \
PS pump x Cylinder head for bolt 39 400 29
\
 \
 for nut 43 440 32
\
 \
Propeller shaft x Transmission  79 805 58\
 \

Propeller shaft x Differential
  
79
 
805
 
58\
 \

Propeller shaft x Body
  
37
 
375
 
27\
 \
Center floor crossmember brace x Body  13 130 9\
 \
Fuel inlet hose x Fuel tube  30 310 22\
 \
TWC (Front) x Exhaust manifold  62 530 46\
 \
Front exhaust pipe x TWC (Front)  43 440 32\
 \
Front exhaust pipe support bracket x Transmission  43 440 32\
 \
Front exhaust pipe x Center Exhaust pipe  43 440 32\
 \
Center exhaust pipe x Tailpipe  44 195 14
\
 \
Main heated oxygen Exhaust manifold  44 450 33
\
 \
Sub heated oxygen sensor x Front exhaust pipe  44 450 33
±
1UZ ± FE ENGINE ENGINE MECHANICALEG±211
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