On-Vehicle Inspection

WARNING: This page is about a different car, the 2002 Toyota Sequoia. 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 . See Fig 1.
Run engine at approx. 2,000 rpm .
Set blower speed control switch to "HI" position .
Set temperature control lever to "MAX. COOL" position .
A/C switch ON .

Fig 1: Locating Pressure Switch Connector & Identifying Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Inspect pressure switch operation , see Fig 2:
1. Connect the positive (+) lead from the ohmmeter to terminal 4 and negative (-) lead to terminal 1. See Fig 1.
2. Check continuity between terminals when refrigerant pressure is changed, as shown in the illustration.
  If operation is not as specified, replace the pressure switch.
Fig 2: Testing Pressure Switch Operation
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Cooling fan control :
Inspect pressure switch operation. See step 7.
Stop engine and set off manifold gauge set .
Connect connector to pressure switch , see Fig 3:
1. Connect the positive (+) lead from the ohmmeter to terminal 2 and the negative (-) lead to terminal 3. See Fig 1.
2. Check continuity between terminals when refrigerant pressure is changed, as shown in the illustration.
  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: Testing Cooling Fan Control
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002