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/InstallationRefrigerant System Service Warnings
Handling Refrigerant
Avoid breathing air conditioning refrigerant or lubricant vapor. Exposure
may irritate eyes, nose and throat. Also, due to environmental concerns, we
urge use of recovery/recycling/recharging equipment when draining HFC-134a from
the air conditioning system. If a ...
Accessory Socket
Purpose
By inserting the plug of an electrical device, 12 V (maximum 120 W) of power
is supplied enabling use of the electrical device in the vehicle.
Function
Front accessory socket
When the ignition is switched to ACC or ON (engine off or on), 12 V (maximum
120 W) of pow ...
Brake Fluid Pressure Sensor Inspection
1. Switch the ignition to off.
2. Remove the clips.
3. Set the splash shield out of the way.
4. Disconnect the brake pipe from the LF brake hose.
5. Remove the clip.
6. Remove the LF brake hose from the bracket.
7. Detach the brake pipe from the pipe holder.
8. Install the SST ...