Inspection Procedure

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.

Check compressor.
Preparation
1. Check compressor drive belt tension. See ON-VEHICLE INSPECTION OF DRIVE BELT .
2. Check if the compressor does not lock during operation with engine started and blower switch and A/C switch ON.
  1. NG: Adjust drive belt tension or repair compressor.
  2. OK: Go to step c .
3. Check compressor lock sensor.
  PREPARATION: Disconnect compressor lock sensor connector.
  
  Check: Measure resistance between terminals 2 and 4 of compressor lock sensor connector. If OK , resistance : at 20 °C (68 °F) : 65 - 125 Ω.
  
  Fig 1: Locating & Testing Compressor Lock Sensor
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Reference : Inspection using oscilloscope
  
  During cranking or idling, measure voltage between terminals LOCK and SGLOCK of A/C amplifier.
  
  NOTE: The correct waveform appears as shown in Fig 2.
  
  Fig 2: Identifying Compressor Lock Sensor Waveform Indicating Proper Operation
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  1. NG: Replace compressor.
  2. If OK , go to step d.
4. Check harness and connector between A/C amplifier and compressor lock sensor . See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION .
  1. NG: Repair or replace harness or connector.
  2. If OK , proceed to next circuit inspection shown on problem symptoms table. See PROBLEM SYMPTOMS TABLE . However, if DTC 22 is displayed, check and replace A/C amplifier.