Inspection Procedure

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.

Check Voltage Between Terminal PSW And GND Of Integration Control And Panel
Preparation:
1. Install the manifold gauge set.
2. Remove the center cluster integration panel with connectors still connected.
Check:
1. Turn ignition switch to ON.
2. Check voltage between terminals PRE and GND of integration control and panel connector when A/C refrigerant pressure is changed.
  
  Fig 1: Locating Integration Control And Panel Connector PRE & GND
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
OK:

The voltage changes with refrigerant pressure, as shown in the diagram below.

Fig 2: Diagramming Relationship Of Voltage To Refrigerant Temperature
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Go to step 2.
2. OK: Proceed to next circuit inspection shown on problem symptoms table. See PROBLEM SYMPTOMS TABLE . However, if DTC 23 is displayed, check and replace integration control and panel.
Check Pressure Switch
Preparation:

Disconnect pressure switch connector.

Check:
1. Turn ignition switch ON.
2. Check continuity between terminals 1 and 2 of pressure switch when A/C refrigerant pressure is changed.
  
  Fig 3: Locating Pressure Switch Terminals 1 & 2
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
OK:

The continuity changes with refrigerant pressure as shown below.

Fig 4: Diagramming Relationship Of Continuity To Refrigerant Pressure
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Replace pressure switch.
2. OK: Go to next step.
Check Harness And Connector Between Integration Control And Panel And Pressure Switch
1. NG: Repair or replace harness or connector.
2. OK: Check and replace integration control and panel.