Air Conditioning Compressor Magnetic Clutch Circuit: Procedure

1. Connect Techstream to the DLC3.
2. Turn the ignition switch on (IG) and turn Techstream main switch on.
3. Turn the A/C switch ON and OFF.
4. Select the item below in the Data List, and read the display on Techstream.
   DATA LIST / ENGINE:
   
   

   Tester Display	Measure Item/Range	Normal Condition	Diagnostic Note
   A/C Signal (A/C Signal)	A/C signal / ON or OFF	ON: A/C ON OFF: A/C OFF	-

   OK

   The display is as specified in the normal condition column.

NG → See step   8 

OK: Go to next step 

1. Remove the A/C NO. 2 fuse from the instrument panel junction block.
2. Measure the resistance of the fuse.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   A/C NO. 2 fuse	Always	Below 1 Ω

NG → REPLACE FUSE (A/C NO. 2) 

OK: Go to next step 

1. Remove the MG/CLT relay from the engine room relay block and junction block.
   Fig 1: Inspecting Magnet-Clutch Relay (MG/CLT)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Specified Condition
   3 - 5	10 kΩ or higher
   3 - 5	Below 1 Ω (when battery voltage is applied to terminals 1 and 2)

NG → REPLACE MAGNET-CLUTCH RELAY (MG/CLT) 

OK: Go to next step 

1. Disconnect the connector from the air conditioning amplifier.
   Fig 2: Checking Harness And Connector (A/C Amplifier - Battery)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Condition	Specified Condition
   D37-20 (MGC) - Body ground	Ignition switch off	Below 1 V
   D37-20 (MGC) - Body ground	Ignition switch on (IG)	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR CONDITIONING AMPLIFIER - BATTERY) 

OK: Go to next step 

1. Reconnect the connector to the air conditioning amplifier.
   Fig 3: Checking Air Conditioning Amplifier

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Condition	Specified Condition
   D37-20 (MGC) - Body ground	Ignition switch on (IG) A/C switch: OFF	11 to 14 V
   D37-20 (MGC) - Body ground	Ignition switch on (IG) A/C switch: ON	Below 1 V

NG → See step   9 

OK: Go to next step 

1. Disconnect the connector from the compressor and magnetic clutch.
   Fig 4: Checking Compressor And Magnetic Clutch

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance of the connector.
3. When connector terminal 3 (MG+) is connected to the positive (+) battery terminal, and the body ground is connected to the negative (-) battery terminal, check that the following occurs: 1) the magnetic clutch's operating sound is emitted, and 2) the magnetic clutch's hub and rotor lock.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   B66-3 (MG+) - Body ground	Always	Below 1 Ω

NG → See step   10 

OK: Go to next step 

1. Remove the MG/CLT relay from the engine room relay block and junction block.
   Fig 5: Identifying MG/CLT Relay From The Engine Room Relay Block And Junction Block

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Turn the ignition switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Condition	Specified Condition
   Relay block MG/CLT relay terminal 5 - Body ground	Always	11 to 14 V
   Relay block MG/CLT relay terminal 1 - Body ground	Always	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPAIR OR REPLACE HARNESS OR CONNECTOR