AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System) Air Conditioning Compressor Magnetic Clutch Circuit

DESCRIPTION

When the A/C amplifier is turned on, a magnetic clutch ON signal is sent from the MGC terminal of the A/C amplifier. Then, the MGC relay turns on to operate the magnetic clutch.

INSPECTION PROCEDURE

PROCEDURE

1. Click here

   READ VALUE USING INTELLIGENT TESTER

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the ignition switch on (IG) and turn the intelligent tester 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 the intelligent tester.

      Table 1. 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.

   
   
   • OKClick here
   • NGClick here
2. Click here

   INSPECT FUSE (A/C NO. 2)

   
   

   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 Always Below 1 Ω

   
   
   • OKClick here
   • NGClick here
3. Click here

   INSPECT MAGNET-CLUTCH RELAY (MG CLT)

   
   
   1. 

      Remove the MG CLT relay from the engine room No. 1 relay block and junction block.

   2. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition 3 - 5 When battery voltage is not applied to terminals 1 and 2 10 kΩ or higher 3 - 5 When battery voltage is applied to terminals 1 and 2 Below 1 Ω

   
   
   • OKClick here
   • NGClick here
4. Click here

   CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BATTERY)

   
   
   1. 

      Disconnect the connector from the air conditioning amplifier.

   2. Measure the voltage according to the value(s) in the table below.

      Standard voltage
      Tester Connection Condition Specified Condition D33-20 (MGC) - Body ground Ignition switch off Below 1 V D33-20 (MGC) - Body ground Ignition switch on (IG) 11 to 14 V

   
   
   • OKClick here
   • NGClick here
5. Click here

   INSPECT AIR CONDITIONING AMPLIFIER

   
   
   1. 

      Reconnect the connector to the air conditioning amplifier.

   2. Measure the voltage according to the value(s) in the table below.

      Standard voltage
      Tester Connection Condition Specified Condition D33-20 (MGC) - Body ground Ignition switch on (IG) Air conditioning switch: OFF 11 to 14 V D33-20 (MGC) - Body ground Ignition switch on (IG) Air conditioning switch: ON Below 1 V

   
   
   • OKClick here
   • NGClick here
6. Click here

   INSPECT A/C COMPRESSOR

   
   
   1. 

      Disconnect the connector from the air conditioning compressor.

   2. Measure the resistance of the connector.

   3. When connector terminal 1 (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 B44-1 (MG+) - Body ground Always Below 1 Ω

   
   
   • OKClick here
   • NGClick here
7. Click here

   CHECK HARNESS AND CONNECTOR (ENGINE ROOM R/B AND J/B - BATTERY)

   
   
   1. 

      Remove the MG CLT relay from the engine room No. 1 relay block and junction block.

   2. 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 Ignition switch on (IG) 11 to 14 V Relay block MG CLT relay terminal 1 - Body ground Ignition switch on (IG) 11 to 14 V

   
   
   • OKClick here
   • NGClick here
8. Click here

   REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM R/B AND J/B - A/C COMPRESSOR)

9. Click here

   PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLEClick here

10. Click here

    REPLACE FUSE (A/C NO. 2)

11. Click here

    REPLACE MAGNET-CLUTCH RELAY (MG CLT)

12. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

13. Click here

    REPLACE AIR CONDITIONING AMPLIFIERClick here

14. Click here

    REPLACE AIR CONDITIONING COMPRESSOR

15. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM R/B AND J/B - BATTERY)