On-Vehicle Inspection

WARNING: This page is about a different car, the 2004 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.

SET ON MANIFOLD GAUGE SET (See MANIFOLD GAUGE SET )
DISCONNECT CONNECTOR FROM PRESSURE SWITCH
RUN ENGINE AT APPROX. 1,500 RPM

Fig 1: Disconnecting Connector From Pressure Switch
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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 .
If operation is not as specified, replace the pressure switch.

Fig 2: Magnetic Clutch Control: Pressure Switch Operation Diagram
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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 .
If operation is not as specified, replace the pressure switch.
STOP ENGINE AND SET OFF MANIFOLD GAUGE SET
CONNECT CONNECTOR TO PRESSURE SWITCH

Fig 3: Cooling Fan Control: Pressure Switch Operation Diagram
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002