On-Vehicle Inspection Of Pressure Switch

WARNING: This page is about a different car, the 2002 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.

Set on manifold gauge set . See SET ON MANIFOLD GAUGE SET .
Disconnect connector from pressure switch .

Fig 1: Locating Pressure Switch Connector & Identifying Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Run engine at approximately 1,500 RPM
Magnetic clutch control:
Inspect pressure switch operation:
1. Connect the positive (+) lead from the ohmmeter to terminal 4 and the negative (-) lead to terminal 1
2. Check continuity between terminals when refrigerant pressure is changed, as shown in Fig 2.
  
  Fig 2: Magnetic Clutch Control Continuity Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
If operation is not as specified, replace the pressure switch.
Cooling fan control:
Inspect pressure switch operation
1. Connect the positive (+) lead from the ohmmeter to terminal 2 and the negative (-) lead to terminal 3.
2. Check continuity between terminals when refrigerant pressure is changed, as shown in Fig 3.
  
  Fig 3: Condenser Fan Control Continuity Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
If operation is not as specified, replace the pressure switch.
Stop engine and set off manifold gauge set .
Connect connector to pressure switch .