ECD SYSTEM Air Conditioning Signal Circuit

DESCRIPTION

When the A/C compressor is on, the A/C amplifier sends the A/C signal to the ECM and the ECM increases the fuel injection volume to improve driveability during engine idling.

WIRING DIAGRAM

A0095ZXE03

INSPECTION PROCEDURE

When using intelligent tester:

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (AIR CONDITIONING SIGNAL)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine.

    3. Turn the A/C switch on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / A/C SIG.

      Result
      Switch Condition A/C SIG
      A/C switch off OFF
      A/C switch on ON

    NG

    CHECK ECM (AC1 VOLTAGE) Click here

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

  2. CHECK ECM (AC1 VOLTAGE)


    1. A009AF3E99
      Text in Illustration
      *a

      Component with harness connected

      (ECM)

      Start the engine.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G62-2 (AC1) - Body ground A/C switch on Below 1.5 V
      G62-2 (AC1) - Body ground A/C switch off 7.5 to 14 V

    NG

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

    OK

    REPLACE ECM Click here

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


    1. Disconnect the A/C amplifier connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      G25-17 (AC1) - G62-2 (AC1) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      G25-17 (AC1) or G62-2 (AC1) - Body ground Always 10 kΩ or higher

    4. Reconnect the A/C amplifier connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE AIR CONDITIONING AMPLIFIER Click here

When not using intelligent tester:

PROCEDURE


  1. CHECK ECM (AC1 VOLTAGE)


    1. A009AF3E99
      Text in Illustration
      *a

      Component with harness connected

      (ECM)

      Start the engine.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G62-2 (AC1) - Body ground A/C switch on Below 1.5 V
      G62-2 (AC1) - Body ground A/C switch off 7.5 to 14 V

    NG

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

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

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


    1. Disconnect the A/C amplifier connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      G25-17 (AC1) - G62-2 (AC1) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      G25-17 (AC1) or G62-2 (AC1) - Body ground Always 10 kΩ or higher

    4. Reconnect the A/C amplifier connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE AIR CONDITIONING AMPLIFIER Click here