ECD SYSTEM Air Conditioning Signal Circuit

DESCRIPTION

When the A/C compressor is on, the air conditioning 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

B007RNGE05

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING GTS (A/C SIGNAL)


    1. Connect the GTS to the DLC3.

    2. Start the engine.

    3. Turn the air conditioning switch on.

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

    5. Read the value.

      Result
      A/C Compressor Display
      OFF A/C Signal OFF
      ON A/C Signal ON

    NG

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

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

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


    1. Disconnect the air conditioning amplifier assembly connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H19-8 (AC1) - B74-47 (AC1) Always Below 1 Ω
      H19-8 (AC1) or B74-47 (AC1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY (CHECK VOLTAGE)


    1. B007T13E01
      Text in Illustration
      *a

      Component with harness connected

      (Air Conditioning Amplifier Assembly)

      Start the engine.

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

      Standard Voltage
      Tester Connection Connection Specified Condition
      H19-8 (AC1) - Body ground A/C compressor ON 1.3 to 2.6 V
      H19-8 (AC1) - Body ground A/C compressor OFF 3.7 to 4.5 V

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

    REPLACE ECM Click here