coolant temperature TOYOTA CAMRY V20 1986 Service Information

4. INSPECT WATER TEMPERATURE SWITCH
(a) Disconnect the switch connector.
(b) Using an ohmmeter, measure the resistance between
terminal 1 and body ground.
Coolant temperature:
Below 109
°F (43°C) 0

Above 131°F (55°C)
8

(c) Connect the switch connector.(e) Turn on the ignition switch and disconnect the water
temperature switch wire.
(f) Confirm that operation sounds of the solenoid can be
heard if the O/D main switch is repeatedly turn on
and off.
(g) Turn off the ignition switch and connect the water
temperature switch wire.
2. INSPECT O/D MAIN SWITCH
(a) Remove the console box.
(b) Using an ohmmeter, measure the resistance between
terminals 1 and 3.
wSwitch ON ± Resistance: 8


wSwitch OFF± Resistance: 0

3. INSPECT O/D OFF INDICATOR
(a) Turn on the ignition switch.
(b) Turn off the O/D main switch.
(c) Check that the O/D OFF indicator lights.
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A140L)AT±37

3. INSPECT EACH UP±SHIFT POSITION
(a) Warm up the engine.
Coolant temperature: 176
°F (80°C)
(b) Turn the O/D switch to ºONº.
(c) Place the pattern select switch in ºNormalº and the shift
lever into the D range.
(d) During a road test (above 10 km/h or 6 mph) check that
voltage at the ECT terminal is as indicated below for
each up±shift position.
If the voltage rises from 0V to 7V in the sequence
shown, the control system is okay.
The chart on the left shows the voltmeter reading and
corresponding gears. .
HINT: Determine the gear position by a light shock or
change in engine rpm when shifting. The lock±up clutch
will turn ON only infrequently during normal 2nd and 3rd
gear operation. To trigger this action, press the acceler-
ator pedal to 50% or more of its stroke. At less than
50%, the voltage may change in the sequence 2V ± 4V
± 6V ± 7V. 2. INSPECT BRAKE SIGNAL
(a) Depress the accelerator pedal until the ECT terminal
indicates 8V.
(b) Depress the brake pedal and check the voltage read-
ing from the ECT terminal.
(c) Brake pedal depressed . . . . . . . . . . 0V
Brake pedal released . . . . . . . . . . . . 8V
If not as indicated, there is a malfunction in either the
stop light switch or circuit.
INSPECTION OF Tt TERMINAL VOLTAGE
1. INSPECT THROTTLE POSITION SENSOR SIGNAL
(a) Turn the ignition switch to ON. Do not start the engine.
(b) Connect a voltmeter to terminals Tt and E1.
(c) While slowly depressing the accelerator pedal,
check that ECT terminal voltage rises in sequence.
if the voltage does not change in proportion to the
throttle opening angle, there is a malfunction in the
throttle position sensor or circuit.
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A140E)AT±31

ROAD TEST (A140E)
NOTICE: Perform the test at normal operating fluid
temperature (122 ± 176°F or 50 ± 84°C). .
1. D RANGE TEST IN NORM AND PWR PATTERN
RANGES
Shift into the D range and hold the accelerator pedal
constant at the full throttle valve opening position.
Check the following:
(a) 1±2, 2±3 and 3±O/D up±shifts should take place, and
shift points should conform to those shown in the au-
tomatic shift schedule. (See page AT±49)
Conduct a test under both Normal and Power patterns.
HINT:
There is no O/D up±shift when coolant temperature is
below 122
°F (50°C).
There is no lock±up when the vehicle speed is 10 km/h (6
mph) less than the set cruise control speed.
EVALUATION
(1) If there is no 1 ± 2 up±shift:
wNo. 2 solenoid is stuck
w1±2 shift valve is stuck
(2) If there is no 2 ± 3 up±shift:
w No. 1 solenoid is stuck
w2±3 shift valve is stuck
(3) If there is no 3 ± O/D up±shift:
w3±O/D shift valve is stuck
(4) If the shift point is defective:
wThrottle valve, 1±2 shift valve, 2±3 .shift valve, 3±
wO/D shift valve etc., are defective
(5) If the lock±up is defective:
wLock±up solenoid is stuck
wLock±up relay valve is stuck
(b) In the same manner, check the shock and slip at the 1
±2, 2 ± 3 and 3 ± O/D up±shifts.
EVALUATION
If the shock is excessive:
wLine pressure is too high
wAccumulator is defective
wCheck ball is defective
(c) Run at the D range lock±up or O/D gear and check for
abnormal noise and vibration.
HINT: The check for the cause of abnormal noise and
vibration must be make with extreme care as it could
also be due to loss of balance in the drive shaft, tire,
torque converter, etc.
± AUTOMATIC TRANSAXLETroubleshooting (Mechanical System Tests) (A140L and
A140E)AT±43

ROAD TEST (A540E and A540H)
NOTICE: Perform the test at normal operating fluid temperature
(122 ± 176°F or 50 ± 80°C).
1. D RANGE TEST IN NORM AND PWR PATTERN
RANGES
Shift into the D range and hold the accelerator pedal
constant at the full throttle valve opening position.
Check the following:
(a) 1±2, 2±3 and 3±O/D up±shifts should take place, and shift
points should conform to those shown in the automatic
shift schedule. (See page AT±230)
Conduct a test under both Normal and Power. patterns.
HINT:
wThere is no O/D up±shift and lock±up when the coolant
temp. is below 140
°F (60°C) (A540E) or 122°I= (50°C)
(A540H).
wWhen the coolant temp. is below 140°F (600C) or
122°F (50°C) (A540H), the shift point is lower than specified in
the automatic shift schedule.
EVALUATION
(1) If there is no 1 ± 2 up±shift:
wNo. 2 solenoid is stuck
w1±2 shift valve is stuck
(2) If there is no 2 ± 3 up±shift:
wNo. 1 solenoid is stuck
w2±3 shift valve is stuck
(3) If there is no 3 ± O/D up±shift:
w3±4 shift valve is stuck
(4) If the shift point is defective:
wThrottle valve, 1±2 shift valve, 2±3 shift valve, 3±4
shift valve etc., are defective
(5) If the lock±up is defective:
wLock±up solenoid is stuck .
wLock±up relay valve is stuck
(b) In the same manner, check the shock and slip at the 1
±2, 2 ± 3 and 3 ± O/D up±shifts.
EVALUATION
If the shock is excessive:
wLine pressure is too high
wAccumulator is defective
wCheck ball is defective
(c) Run at the D range lock±up or 0/C) gear and check for abnor-
mal noise and vibration.
HINT: The check for the cause of abnormal noise and vibra-
tion must be make with extreme care as it could also be due
to loss of balance in the drive shaft, tire, torque converter,
etc.
± AUTOMATIC TRANSAXLETroubleshooting (Mechanical System Tests) (A540E and
A540H)AT±227

3. INSPECT EACH UP±SHIFT POSITION
(a) Warm up the engine.
Coolant temperature: 176
°F (80°)
(b) Turn the O/D switch to ºONº.
(c) Place the pattern select switch in ºNormalº and the shift
lever into the D range.
(d) During a road test (above 10 km/h or 6 mph) check that volt-
age at the Tt terminal is as indicated below for each up±
shift position.
If the voltage rises from 0V to 7V in the sequence shown,
the control system is okay.
The chart on the left shows the voltmeter reading and cor-
responding gears.
HINT: Determine the gear position by a fight shock or
change in engine rpm when shifting. The lock±up clutch will
turn ON only infrequently during normal 2nd and 3rd gear
operation. To trigger this action, press the accelerator pedal
to 50% or more of its stroke. At less than 50%, the voltage
may change in the sequence 2v ± 4V ± 6V ± 7V. 2. INSPECT BRAKE SIGNAL
(a) Depress the accelerator pedal until the Tt terminal indi-
cates 8V.
(b) Depress the brake pedal and check the voltage read-
ing from the Tt terminal.
Brake pedal depressed ...... 0V
Brake pedal released . . . . . . . . 8V
If not as indicated, there is a malfunction in either the
stop light switch or circuit.
INSPECTION OF ECT OR Tt TERMINAL
VOLTAGE
1. INSPECT THROTTLE POSITION SENSOR SIGNAL
(a) Turn the ignition switch to ON. Do not start the engine.
(b) Connect a voltmeter to terminals Tt and E1.
(c)while slowly depressing the accelerator pedal, check
that Tt terminal voltage rises in sequence.
If the voltage does not change in proportion to the
throttle opening angle, there is a malfunction in the
throttle position sensor or circuit.
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±215

The cooling system is composed of the water jacket (inside the cylinder block and cylinder head), radiator,
water pump, thermostat, electric fan, hoses and other components.
Coolant which is heated in the water jacket is pumped to the radiator, through which an electric fan blows air
to cool the coolant as it passes through. Coolant which has been cooled is then sent back to the engine by
the water pump, where it cools the engine.
The water jacket is a network of channels in the shell of the cylinder block and cylinder head through which
coolant passes. It is designed to provide adequate cooling of the cylinders and combustion chambers which
become heated during engine operation.
RADIATOR
The radiator performs the function of cooling the coolant which has passed through the water jacket and be-
come hot, and it is mounted in the front of the vehicle. The radiator consists of an upper tank and lower tank,
and a core which connects the two tanks. The upper tank contains the inlet for coolant from the water jacket
and the filler inlet. It also has a hose attached through which excess coolant or steam can flow. The lower
tank has an outlet and drain cock for the coolant. The core contains many tubes through which coolant flows
from the upper tank to the lower tank as well as cooling fins which radiate heat away from the coolant in the
tubes.
The air sucked through the radiator by the electric fan, as well as the wind generated by the vehicle's travel,
passes through the radiator, cooling the coolant. Models with automatic transmission include an automatic
transmission fluid cooler built into the lower tank of the radiator. A fan with an electric motor is mounted be-
hind the radiator to assist the flow of air through the radiator. The fan operates when the coolant tempera-
ture becomes high in order to prevent it from becoming too high.
RADIATOR CAP
The radiator cap is a pressure type cap which seals the radiator, resulting in pressurization of the radiator as
the coolant expands. The pressurization prevents the coolant from boiling even when the coolant tempera-
ture exceeds 100°C (212°F). A relief valve (pressurization valve) and a vacuum valve (negative pressure
valve) are built into the radiator cap. The relief valve opens and lets steam escape through the overflow pipe
when the pressure generated inside the cooling system exceeds the limit (coolant temperature: 110 ±
120°C, 230 ± 248°F, pressure; 0.3 ±1.0 kg/cm
2, 4.3 ±14.2 psi, 29.4 ± 98.1 kPa). The vacuum valve opens to
alleviate the vacuum which develops in the coolant system after the engine is stopped and the coolant tem-
perature drops.
The valves's opening allows the coolant in the reservoir tank to return to the cooling system.
RESERVOIR TANK
The reservoir tank is used to catch coolant which overflows the cooling system as a result of volumetric ex-
pansion when the coolant is heated. The coolant in the reservoir rank returns to the radiator when the cool-
ant temperature drops, thus keeping the radiator full at all times and avoiding needless coolant loss. Check
the reservoir tank level to find out if the coolant needs to be replenished.
WATER PUMP
The water pump is used for forced circulation of coolant through the cooling system. It is mounted on the
front of the cylinder block and driven by a timing belt.
THERMOSTAT
The thermostat has a wax type by±pass valve and is mounted in the water inlet housing. The thermostat in-
cludes a type of automatic valve operated by fluctuations in the coolant temperature. This valve closes when
the coolant temperature drops, preventing the circulation of coolant through the engine and thus permitting
the engine to warm up rapidly. The valve opens when the coolant temperature has risen, allowing the cir-
culation of coolant. Wax inside the thermostat expands when heated and contracts when cooled. Heating
the wax thus generates pressure which overpowers the force of the spring which keeps±the valve closed,
thus opening the valve. When the wax cools, its contraction causes the force of the spring to take effect
once more, closing the valve. The thermostat in this engine operates at a temperature of 82°C (180°F).
± COOLING SYSTEMDescriptionCO±3

REMOVAL OF WATER PUMP
1. DRAIN ENGINE COOLANT (See page CO±4)
2. DISCONNECT WATER TEMPERATURE SWITCH
CONNECTOR
3. DISCONNECT RADIATOR LOWER HOSE FROM
WATER INLET HOUSING
4. REMOVE TIMING BELT, PULLEYS
(See pages EM±23 to 26)
5. REMOVE WATER PUMP AND WATER PUMP COVER
ASSEMBLY .
(a) Remove the two nuts holding the pump to the water by±
pass pipe.
WATER PUMP (3S±FE)
COMPONENTS
± COOLING SYSTEMWater Pump (3S±FE)CO±6

(b) Apply a fight coat of engine oil on the 4±ring of the water
by±pass pipe.
(c) Connect the pump cover to the water by±pass pipe. Do
not install the nuts yet.
(d) Install the water pump with the three bolts. Torque the
bolts in the sequence shown.
Torque: 95 kg±cm (82 in.±Ib, 9.3 N±m)
3. INSTALL PULLEYS AND TIMING BELT (See pages
EM±29 to 33)
4. CONNECT RADIATOR LOWER HOSE
5. CONNECT WATER TEMPERATURE SWITCH
CONNECTOR
6. FILL WITH ENGINE COOLANT (See page CO±5) (e) Install the two nuts holding the pump cover to the water
by±pass pipe.
Torque: 95 kg±cm (82 in.±Ib, 9.3 N±m)
± COOLING SYSTEMWater Pump PS±FE)CO±8

THERMOSTAT (3S±FE)
REMOVAL OF THERMOSTAT
1. DRAIN ENGINE COOLANT (See page CO±4)
2. DISCONNECT WATER TEMPERATURE SWITCH
CONNECTOR
3. DISCONNECT RADIATOR FROM WATER INLET
HOUSING
4. REMOVE WATER INLET HOUSING
Remove the two nuts and water inlet housing from the
waterpump.
5. REMOVE THERMOSTAT AND GASKET
INSPECTION OF THERMOSTAT
INSPECT THERMOSTAT
HINT: The thermostat is numbered with the valve opening
temperature.
(a) Immerse the thermostat in water and gradually heat the wa-
ter.
(b) Check the valve opening temperature.
Valve opening temperature:
80 ± 845C (176 ± 1835F)
If the valve opening temperature is not as specified, re-
place the thermostat.
(e) Check the valve lift.
Valve lift:
8 mm (0.31 in.) or more at 95°C (203°F)
If the valve lift is less than specification, replace the
thermostat.
INSTALLATION OF THERMOSTAT
1. PLACE THERMOSTAT IN WATER INLET HOUSING
(a) Install a new gasket to the thermostat.
(b) Align the jiggle valve of the thermostat with protrusion of the
water inlet housing and, insert the thermostat in the water
inlet housing.
2. INSTALL WATER INLET HOUSING AND THERMOSTAT
ASSEMBLY
Install the water inlet housing and thermostat assembly with
the two nuts.
Torque: 90 kg±cm (78 in.±Ib, 8.8 N±m)
3. CONNECT RADIATOR LOWER HOSE
4. CONNECT WATER TEMPERATURE SWITCH
CONNECTOR
5. FILL WITH ENGINE COOLANT (See page CO±5)
6. START ENGINE AND CHECK FOR LEAKS
± COOLING SYSTEMThermostat (3S±FE)CO±12

(b) Check the valve opening temperature
Valve opening temperature:
80 ± 845C (176 ± 1835F)
If the valve opening temperature is not as specified, re-
place the thermostat.
(c) Check the valve lift.
Valve lift:
8.5 mm (0.335 in.) or more at 95
°C (203°F)
If the valve lift is less than specification, replace the ther-
mostat.
(d) Check that the valve spring is tight when the thermostat
is fully closed.
THERMOSTAT (2VZ±FE)
REMOVAL OF THERMOSTAT
1. DRAIN ENGINE COOLANT (See page CO±5)
2. REMOVE WATER INLET PIPE
(See steps 2 and 4 on page CO±9)
3. DISCONNECT WATER TEMPERATURE SENSOR
CONNECTOR
INSPECTION OF THERMOSTAT
INSPECT THERMOSTAT
HINT: The thermostat is numbered with the valve opening
temperature.
(a) Immerse the thermostat in water and gradually heat the wa-
ter. 4. REMOVE WATER INLET
Remove the three nuts and water inlet from the water
pump.
5. REMOVE THERMOSTAT AND GASKET
± COOLING SYSTEMThermostat (2VZ±FE)CO±13