coolant TOYOTA CAMRY V20 1986 Service Information

Disconnect solenoid wire connector and road test.
Does the transaxle operate in the respective gear
when in the following ranges while driving?
D range .... Overdrive
2 range .... Overdrive
L range .... 1 st gear
TROUBLESHOOTING FLOW±CHART (A540E)
Trouble No. 1 No Shifting
Is voltage between Engine and ECT ECU
terminals BK and E1 as follows?
0V: Brake pedal released
10 ± 14V: Brake pedal depressed
Connect solenoid wire connector and road test.
Does Tt terminal voltage rise from 0V to
7V in sequence?Warm up engine
Coolant temp.: 176°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°C)
Connect a voltmeter to terminals Tt and E1.
Does Tt terminal voltage vary with changes in
throttle opening? (See page AT±215)
wECU power source and ground faulty
wThrottle position signal faulty
wTt terminal wire open or short
Are there 10 ± 14V between
Engine and ECT ECU terminals 2 ± E
when in the D range?
Are there 10 ± 14V between Engine and ECT
ECU terminals L ± Ex when in the D range?
wNeutral start switch circuit faulty
wNeutral start switch faultyProceed to trouble No. 3
(See page AT±209)
Try another Engine and ECT ECUw Transaxle faulty
wSolenoid faultyBrake signal faulty
Transaxle faulty
Ye s
Ye s
Ye s
Ye s Ye s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±207

Check voltage between Engine and ECT ECU
terminals PWR and E1.
Power pattern: 10 ± 14V
Normal pattern: 1VIs voltage between Engine and ECT ECU
terminals BK and E1 as follows?
0V: Brake pedal released
1V: Brake pedal depressed Warm up engine
Coolant temp.: 176°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°C)
Connect a voltmeter to terminals Tt and El.
Does Tt terminal voltage vary with changes in
throttle opening? (See page AT±215)
ECU power source and ground faulty
Throttle position signal faulty
Tt terminal wire open or short
Faulty Engine and ECT ECU
Faulty transaxle
Shift point too high or too Low
Faulty pattern select switch systemBrake signal
faulty
Trouble No. 2
Ye s Ye s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±208

Road test
Connect a voltmeter to terminals Tt and El.
Is there 7, 5 or 3V in the lock±up range while driv-
ing?
Is voltage between Engine and ECT ECU BK
and E1 terminals as follows?
Brake pedal depressed: 10 ± 14V
Brake pedal released: OV Warm up engine
Coolant temp.: 176°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°C)
wFaulty ECU power source and ground
wFaulty throttle position signalwLock±up solenoid stuck
wFaulty transaxle
w Faulty lock±up mechanism
No lock±up (After warm±up)
Faulty brake signal
Trouble No. 4
Ye sYe s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±210

Disconnect solenoid wire connector and road test.
Does the transaxle operate in the respective gear
when in the following ranges white driving?
D range .... Overdrive
2 range .... Overdrive
L range .... 1 st gear
TROUBLESHOOTING FLOW±CHART (A540H)
Trouble No. 1 No Shifting
Is voltage between ECT ECU terminals BK
and GND as follows?
0V: Brake pedal released
10 ± 14V: Brake pedal depressed
Connect solenoid wire connector and road test.
Does Tt terminal voltage rise from OV to 7V in se-
quence?Warm up engine
Coolant temp.: 176°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°)
Connect a voltmeter to terminals Tt and E1.
Does Tt terminal voltage vary with changes in
throttle opening? (See page AT±215)
wECU power source and ground faulty
wThrottle position signal faulty
wTt terminal wire open or short
Are there 10 ± 14V between ECT
ECU terminals 2L ± GND when in the
D range?
Are there 10 ± 14V between ECT ECU
terminals LL ± GND when in the D range?
wNeutral start switch circuit faulty
wNeutral start switch faultyProceed to trouble No. 3
(See page AT±227) Transaxle faulty
Solenoid faulty
Try another ECT ECUBrake signal
faulty
Transaxle faulty
Ye s
Ye s
Ye s Ye s
Ye s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±211

Is voltage between ECT ECU terminals BK
and GND as follows? .
0V: Brake pedal released
10 ± 14V: Brake pedal depressed
Check voltage between ECT ECU terminals
P and GND.
Power pattern: 10 ~ 14V
Normal pattern: 1 V Warm up engine
Coolant temp.: 176°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°C)
Connect a voltmeter to terminals Tt and E1.
Does Tt terminal voltage vary with changes in
throttle opening? (Seepage AT±21 5)
ECU power source and ground faulty
Throttle position signal faulty
Tt terminal wire open or short
Faulty pattern select switch system
Shift point too high or too low
Faulty ECT ECU
Faulty speed sensorBrake signal
faulty
Trouble No. 2
Ye s
Ye s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±212

Road test
Connect a voltmeter to terminals Tt and E,.
Is there 7, 5 or 3V in the lock±up range while driv-
ing?
Is voltage between ECT ECU BK and GND
terminals as follows?
Brake pedal depressed: 10 ± 14V
Brake pedal released: OV Warm up engine
Coolant temp.: 176°F (80°C)
ATF temp.: 122 ± 176°F (50 ± 80°C)
Trouble No. 4 No lock±up (After warm±up)
w Lock±up solenoid stuck
wFaulty transaxle
wFaulty lock±up mechanism
wFaulty ECU power source and ground
wFaulty throttle position signalFaulty brake signal
Ye sYe s
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±214

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

INSPECTION OF ELECTRONIC CONTROL
COMPONENTS
1. (A540E)
INSPECT VOLTAGE OF TCCS ECU CONNECTOR
(a) Turn on the ignition switch.
(b) Measure the voltage at each terminal.
Coolant temp. 176°F (84°C)
Cruise control main
switch OFFO/D main switch turned OFF O/D main switch turned ON Throttle valve fully closed
Throttle valve fully closed Brake pedal is depressed
Throttle valve fully openMeasuring condition
Brake pedal is released
Throttle valve open
Vehicle movingVehicle moving P, R or N range D, 2 or L range
Standing stillStanding still NORM patternVoltage (V)
PWR pattern Terminal
± AUTOMATIC TRANSAXLE(A540E and A540H)AT±216

3. (A540E)
INSPECT SOLENOID VALVES
(a) Disconnect the connector from Engine and ECT ECU
(b) Measure the resistance between S1, S2, SL and
body ground.
Resistance: 11 ± 15


(e) Apply battery voltage to each terminal.
Check that an operation noise can be heard from
the solenoid.
Center differential control switch AUTO position
Center differential control switch AUTO position Center differential control switch turned OFF
Center differential control switch turned OFF Coolant temp. below 122°F950°0 Throttle valve fully closed to fully open
Coolant temp. above 122°F (50°C0 O/D main switch turned OFF O/D main switch turned ON
Brake pedal is depressed
Brake pedal is releasedMeasuring condition
Except 2 range
Except N range Except P range
Except L range
NORM patternVoltage (V)
PWR pattern Terminal
N range2 range P range
L range
± AUTOMATIC TRANSAXLETroubleshooting (Electronic Control System) (A540E and
A540H)AT±218

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