condition TOYOTA CAMRY V20 1986 Service Information

AT5032
(A540H)
The A540H automatic transaxle design is based on the A540E automatic transaxle and equipped with a
center differential and transfer.
This transaxle has the same hydraulic multiplate clutch in the center differential limiting control mecha-
nism as the A241H automatic transaxle on the Corolla All-Trac/4WD Station Wagon. The fluid pressure
acting on the hydraulic multiplate clutch of the A540H is controlled by the ECT ECU (Electronic Control
Unit) according to the vehicle driving conditions. As a result, torque is distributed to the front and rear
wheels appropriately at all times to maximize the overall performance of the 4WD vehicle.
NOTICE: Special handling methods are necessary for full-time 4WD vehicles during inspection and
maintenance. Instructions concerning these handling methods are given on Camry Repair Manual
(Pub. No. RM199U) on page IN-8.
Hydraulic Multiplate ClutchTransfer Front DifferentialCenter
Differential 4-Speed Planetary Gear
Unit and Hydraulic
Control SystemNo. 1 and No. 2 Center Differential
Control Solenoid ValveCenter Differential ControlECT
ECU No. 1 and No. 2 Shift Control
Solenoid Valves and Lock-up
Control solenoid ValveEngine ECU
Throttle Position
Sensor
Stop Light Switch
Vehicle Speed
Sensors
Mode Select Switch
Neutral Start Switch
O/D Main Switch
Center Deff. Control
Switch Shift Control Sectional View
Sensors
- AUTOMATIC TRANSAXLEDescriptionAT-3

AT1097
OUTIN
D or 2 Range 1st Gear
AT1102
OUTIN
2 Range 2nd Gear
AT1098
OUTIN
D Range 2nd Gear
AT1103
OUTIN
L Range 1st Gear
AT1099
OUTIN
D Range 3rd Gear
AT1101
OUTIN
R Range Reverse Gear
AT1100
OUTIN
D Range O/D Gear
Power from the engine transmitted to the input shaft via the torque converter is then transmitted to the
planetary gears by the operation of the clutch.
By operation of the brake and one-way clutch, either the planetary carrier or the planetary sun gear are
immobilized, altering the speed of revolution of the planetary gear unit.
Shift change is carried out by altering the combination of clutch and brake operation.
Each clutch and brake operates by hydraulic pressure; gear position is decided according to the throttle
opening angle and vehicle speed, and shift change automatically occurs.
The conditions of operation for each gear position are shown on the following illustrations:
- AUTOMATIC TRANSAXLEOperationAT-7

VALVE BODY
Hydraulic Control System

A540E, A540H
The hydraulic control system is composed of the oil pump, the valve body, the solenoid valves, the accu-
mulators, the clutches and brakes, and the governor valve as well as the fluid passages which connect all
of these components.
Based on the hydraulic pressure created by the oil pump, the hydraulic control system governs the hy-
draulic pressure acting on the torque converter, clutches and brakes in accordance with the vehicle driving
conditions.
There are three solenoid valves on the valve body.
The No. 1 and No. 2 solenoid valves are turned on and off by signals from ECU to operate the shift valves
and change the gear shift position.
The No. 3 solenoid valve is operated by signals from the ECU to engage or disengage the lock-up clutch
of the torque converter.

A540H
There are two center differential control solenoid valves on the transfer.
The solenoid valves are adjusting the center differential control pressure.
HYDRAULIC CONTROL SYSTEM
Hydr. pressure control
OIL PUMP
CLUTCHES & BRAKESFluid passage switchingPlanetary gear unit
Torque converter
Throttle Cable
SOLENOID VALVES
ECU
AT-8- AUTOMATIC TRANSAXLEOperation

AIR CONDITIONING SYSTEM
± AIR CONDITIONING SYSTEMAC±1

GENERAL INFORMATION
1. WHEN HANDLING REFRIGERANT (R±12),
FOLLOWING PRECAUTIONS MUST BE OBSERVED.
(a) Do not handle refrigerant in an enclosed area or near
an open flame.
(b) Always wear eye protection.
(e) Be careful that liquid refrigerant does not get in your
eyes or on your skin.
If liquid refrigerant gets in your eyes on your skin;
wDo not rub.
wWash the area with a lot of cool water
wApply clean petroleum jelly to the skin.
wGo immediately to a physician or hospital for
professional treatment.
wDo not attempt to treat yourself.
(d) Discharge refrigerant from the charging valve before
installing the new compressor.
If the refrigerant is not discharged first, compressor oil will
spray out with the refrigerant gas when the plug is r
moved.
(e) Do not use a burner for bending or lengthening opera-
tions on tubes.
If tubes are heated with a burner, a layer of oxidation forms
inside the tube, causing the same kind of trouble as an ac±
cumulation of dust.
3. WHEN TIGHTENING CONNECTING PARTS;
(a) Apply a few drops of compressor oil to O±ring fittings
for easy tightening and to prevent leaking of refriger-
ant gas.
(b) Tighten the nut using two wrenches to avoid twisting
the tube. 2. WHEN REPLACEiNG PARTS ON REFRIGERANT LINE;
(a) Discharge refrigerant slowly before replacement.
(b) Insert a plug immediately in disconnected parts to
prevent entry of moisture and dust.
(c) Do not leave a new condenser or receiver, etc., lying
around with the plug removed.
± AIR CONDITIONING SYSTEMGeneral InformationAC±2

(e) Tighten the O±ring fittings or the bolted type fittings to
the specified torque.
4. WHEN CONNECTING MANIFOLD GAUGE;
(a) Be sure to connect the charging hose end with a pin
to the compressor charging valve.
(b) The letter ºDº engraved near the compressor service
valve indicates the high pressure side, and ºSº indi-
cates the low pressure side. Pay careful attention
when connecting the hose.
(c) Tighten hose by hand.
(d) To prevent loosening of connected hose, do not apply
drops of compressor oil to the seat of connection.
HINT: After connecting the manifold gauge and the refrig±
erant container (service can), discharge any air in the
hoses.
5. WHEN EVACUATING;
Approx. 15 minutes after removal, check the system for
leaks, then take at least another 15 minutes to make sure
the air is fully removed.
6. WHEN HANDLING REFRIGERANT CONTAINER
(SERVICE CAN);
(a) Must never be heated.
(b) Must be kept below 4

°C (1 04°F).
(c) If warming service can with hot water, be careful that
the valve on top of the service can is never immersed
in the water, as the water may permeate into the refrig-
erant cycle.
(d) Empty service cans must never be re±used.
7. WHEN A/C IS ON AND REFRIGERANT GAS IS
BEING REPLENISHED;
(a) If there is not enough refrigerant gas in the refrigerant
cycle, oil lubrication becomes insufficient and com-
pressor burnout may occur, so take care to avoid this.
(b) If the valve on the high pressure side is opened, refrig-
erant flows in reverse and causes the service can to
rupture, so only open and close the vlave on the low
pressure side.
(c) If the service can is inverted and refrigerant is inserted
in a liquid state, the liquid is compressed and the com-
pressor brakes down, so the refrigerant must be in-
serted in a g¿¿seous state.
(d) Be careful not to insert too much refrigerant gas, as
this causes trouble such as inadequate cooling, poor
fuel economy, engine overheat, etc.
8. WHEN USING GAS±CYLINDER TYPE LEAK
DETECTION INSTRUMENT;
(a) As a naked flame is used, first make sure that there are
no flammable substances nearby before using it.
(b) Be careful, as poisonous gas is produced when
refrigerant gas comes in contact with heat parts.
± AIR CONDITIONING SYSTEMGenera! InformationAC±3

AIR CONDITIONING SYSTEM CIRCUIT
(Lever Type on 3S±FE Engine FWD Model)
± AIR CONDITIONING SYSTEMAir Conditioning System CircuitAC±4

(Push Type on 3S±FE Engine FWD Model)
± AIR CONDITIONING SYSTEMAir Conditioning System CircuitAC±5

(Lever Type on 3S±FE Engine All±Trac/4WD Model)
± AIR CONDITIONING SYSTEMAir Conditioning System CircuitAC±6

(Push Type on 3S±FE Engine All±Trac/4WD Model)
± AIR CONDITIONING SYSTEMAir Conditioning System CircuitAC±7