Purpose
The expansion valve atomizes liquid refrigerant to facilitate cooling of the evaporator.
Function
The expansion valve reduces the pressure of liquid refrigerant rapidly to facilitate vaporization of the atomized refrigerant at the evaporator, and adjusts the refrigerant amount sent into the evaporator.
Construction
The expansion valve consists of the following parts:
Diaphragm
Temperature sensor
Shaft
Expansion valve body
Ball valve
Spring

Operation
Adjustment of the refrigerant amount supplied to the evaporator is performed by the ball valve opening angle in the expansion valve.
The opening angle adjustment is performed according to the balance of the following forces:

Refrigerant pressure (Pd) in diaphragm
Refrigerant gas pressure (PI) of evaporator under diaphragm
Spring force (Fs) pushing up ball valve
If the refrigerant gas temperature from the evaporator increases, the expansion valve increases the amount of refrigerant according to the following operations:

The temperature of the temperature sensor tightly sealed against the diaphragm increases.
The refrigerant in the diaphragm warms and the Pd increases.
If this Pd increases more than PI + Fs, the diaphragm is pressed down.
The shaft installed to the temperature sensor end presses down the ball valve.
The amount of refrigerant is increased.
If the refrigerant gas temperature from the evaporator decreases, the expansion valve decreases the amount of refrigerant flow according to the following operation:

The temperature of the temperature sensor tightly sealed against the diaphragm decreases.
The refrigerant temperature in the diaphragm decreases and the Pd decreases.
The Pd decreases less than PI + Fs.
The ball valve installed to the temperature sensor end is pressed up.
The amount of refrigerant is decreased.
Fail-safe
Function not equipped.
Evaporator Inspection
Expansion Valve Removal/InstallationColumn Cover Removal/Installation
1. Pull down the steering wheel.
2. Press the shaded area shown in the figure using your thumb, and lift the upper
column cover in the direction of arrow (1).
3. Pull the upper column cover in the direction of the arrow (2) and remove it
while detaching pins A, tabs B and guides C.
4. ...
Power Window Main Switch
Purpose
Remote control of door glass open/close and power outer mirror adjustment
are possible with occupant seated in the cabin.
Function
Power window main switch
Manual
When the power window main switch is operated for manual open/close operation,
it sends ...
DSC Control
Outline
While a vehicle normally turns safely in response to steering operation,
there are instances when the limits of tire lateral grip is surpassed due to
road surface conditions or vehicle speed, and the influence of evasive steering
to avoid an accident or similar situations.
...