ECD SYSTEM Air Conditioning Cut Control Circuit

DESCRIPTION

This circuit cuts air conditioning operation during vehicle acceleration in order to increase acceleration performance. During acceleration with the vehicle speed at 30 km/h (19 mph) or less and accelerator pedal opening angle at 45° or more, the A/C magnetic switch is turned off for several seconds.

The air conditioning is also controlled by the ECM out putting the engine coolant temperature to A/C amplifier.

WIRING DIAGRAM

A01BG9WE02

INSPECTION PROCEDURE

When using intelligent tester:

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (CHECK OPERATION AIR CONDITIONER CUT CONTROL)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine and air conditioning switch on.

      Tech Tips

      A/C magnetic clutch is turned on.

    3. Select the item "Powertrain/Engine and ECT/Active Test/Control the A/C cut signal" and read its value displayed on the intelligent tester.

    4. Check operation of A/C magnetic clutch cut when air conditioning cut control is operated by the intelligent tester.

      OK
      A/C magnet clutch is turned OFF.

    NG

    INSPECT ECM (CHECK VOLTAGE) Click here

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

  2. INSPECT ECM (CHECK VOLTAGE)


    1. A01BCNHE17

      Start the engine.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      ACT (B8-8) - Body ground Engine at idling 9 to 14 V
      ACT (B8-8) - Body ground IG ON, Engine stop 0 to 3 V

    NG

    CHECK HARNESS AND CONNECTOR (ECM - AIR CONDITIONER AMPLIFIER) Click here

    OK

    REPLACE ECM

  3. CHECK HARNESS AND CONNECTOR (ECM - AIR CONDITIONER AMPLIFIER)


    1. A01BD1TE03

      Disconnect the A/C amplifier H19 connector.

    2. Disconnect the ECM B8 connector.

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

      Standard resistance (Check for open)
      Tester Connection Specified Condition

      ACT (H19-10) (*1) - ACT (B8-8)

      		 Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Specified Condition
      ACT (B8-8) - Body ground 10 kΩ or higher

      Tech Tips

      *1: Terminal arrangement Click here.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    CHECK AND REPLACE AIR CONDITIONER AMPLIFIER

When not using intelligent tester:

PROCEDURE


  1. INSPECT ECM (CHECK VOLTAGE)


    1. A01BCNHE17

      Start the engine.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      ACT (B8-8) - Body ground Engine at idling 9 to 14 V
      ACT (B8-8) - Body ground IG ON, Engine stop 0 to 3 V

    NG

    CHECK HARNESS AND CONNECTOR (ECM - AIR CONDITIONER AMPLIFIER) Click here

    OK

    REPLACE ECM

  2. CHECK HARNESS AND CONNECTOR (ECM - AIR CONDITIONER AMPLIFIER)


    1. A01BD1TE03

      Disconnect the A/C amplifier H19 connector.

    2. Disconnect the ECM B8 connector.

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

      Standard resistance (Check for open)
      Tester Connection Specified Condition

      ACT (H19-10) (*1) - ACT (B8-8)

      		 Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Specified Condition
      ACT (B8-8) - Body ground 10 kΩ or higher

      Tech Tips

      *1: Terminal arrangement Click here.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    CHECK AND REPLACE AIR CONDITIONER AMPLIFIER