Inspection Procedure

1. Connect the hand-held tester to the DLC3.
2. Turn the ignition switch ON and push the hand-held tester main SW ON.
3. Check the A/C magnet clutch input signal using DATA LIST.

   ECM: 

   DISPLAY CODE AND BLOWER LEVEL REFERENCE
   
   

   Item	Measurement Item / Display (Range)	Normal Condition	Diagnostic Note
   A/C SIG	A/C signal / ON or OFF	A/C switch pushed: ON A/C switch released: OFF	-

NG: Go to step   8 

OK: Go to next step 

1. Connect the hand-held tester to DLC3.
2. Turn the ignition switch ON and push the hand-held tester main SW ON.
3. Check the A/C magnet clutch operation permission signal using DATA LIST.

   ECM: 

   ITEMS NORMAL CONDITION TABLE
   
   

   Item	Measurement Item / Display (Range)	Normal Condition	Diagnostic Note
   A/C MAG CLUTCH	A/C magnet clutch / ON or OFF	A/C switch ON: ON A/C switch OFF: OFF	-

NG: REPLACE ECM 

OK: Go to next step 

1. Connect the hand-held tester to DLC3.
2. Turn the ignition switch ON and push the hand-held tester main SW ON.
3. Check the A/C magnet clutch operation using ACTIVE TEST.

   AIR CONDITIONER: 

   ITEMS NORMAL CONDITION TABLE
   
   

   Description	Test Details / Display (Range)	Diagnostic Note
   A/C MAG CLUTCH	Magnet clutch relay / OFF, ON	Operating sound can be heard

NG: Go to step   5 

OK: Go to next step 

1. Check for open and short circuit in the harness and the connector between A/C amplifier and the ECM (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE  

1. Remove the cooler relay assy from the engine room J/B.
2. Check continuity between each pair of terminals as shown in ACTIVE TEST DETAIL (AIR CONDITIONER) .

   Standard: 

   ACTIVE TEST DETAIL (AIR CONDITIONER)
   
   

   Tester connection	Condition	Specified condition
   3 - 5	Always	10 kΩ or higher
   3 - 5	Voltage is applied between terminals 1 and 2	Below 1 Ω (Battery voltage is applied between terminals 1 and 2)

   Fig 1: Inspecting Cooler Relay Assy

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE COOLER RELAY ASSY 

OK: Go to next step 

1. Disconnect the connector from the compressor.
2. Connect the battery positive (+) lead to terminal 3 and the battery negative (-) lead to terminal body ground, then check that the magnetic clutch is engaged.

   Standard: Magnetic clutch is engaged. 

   Fig 2: Identifying Magnet Clutch Assy Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE MAGNET CLUTCH ASSY 

OK: Go to next step 

1. Check for open and short circuit in the harness and the connector between A/C amplifier and body ground (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).

NG: REPLACE HARNESS OR CONNECTOR 

OK: REPLACE AIR CONDITIONING AMPLIFIER 

1. Check for open and short circuit in the harness and the connector between A/C amplifier and the ECM (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).

NG: REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the A/C amplifier with the connectors being connected.
2. Start the engine and push AUTO switch.
3. Measure voltage between terminal AC1 of the A/C amplifier and body ground when the magnetic clutch is turned ON and OFF by operating the A/C switch.

   Standard: 

   TERMINALS RESISTANCE SPECIFICATION
   
   

   Switch operation	Tester connection	Specified condition
   ON	AC1 - Body ground	1.3 to 2.6 V
   OFF	AC1 - Body ground	3.7 to 4.5 V

   Fig 3: Identifying A/C Amplifier Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE AIR CONDITIONING AMPLIFIER 

OK: REPLACE ECM