AUTOMATIC TRANSAXLE SYSTEM ECU Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, voltage from the ECM's MREL terminal is applied to the EFI MAIN relay. This causes the contacts of the EFI MAIN relay to close, which supplies power to terminal +B of the TCM.

WIRING DIAGRAM

A01EKE7E01

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (TCM - BODY GROUND)


    1. A01ELIEE23
      Text in Illustration
      *1

      Front view of wire harness connector

      (to TCM)

      Turn the ignition switch off.

    2. Disconnect the TCM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B40-8 (E1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT ECU TERMINAL VOLTAGE (+B TERMINAL)


    1. A01ELIEE24
      Text in Illustration
      *1

      Front view of wire harness connector

      (to TCM)

      Disconnect the TCM connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      B40-18 (+B) - Body ground Ignition switch ON 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (TCM - ENGINE ROOM JUNCTION BLOCK ASSEMBLY) Click here

    OK

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

  3. CHECK HARNESS AND CONNECTOR (TCM - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)


    1. Turn the ignition switch off.

    2. Disconnect the TCM connector.

    3. Remove the engine room junction block assembly from the engine room relay block.

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

      A01EJ3UE02
      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      B40-18 (+B) - 1E-2 (+B) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B40-18 (+B) or 1E-2 (+B) - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1 Engine Room Junction Block Assembly
      *2

      Front view of wire harness connector

      (to Engine Room Junction Block Assembly)
      *3

      Front view of wire harness connector

      (to TCM)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY


    1. A01EJ4VE01
      Text in Illustration
      *1

      Component without harness connected

      (Engine Room Junction Block Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1E-1 - 1E-2 Always Below 1 Ω

    NG

    REPLACE ENGINE ROOM JUNCTION BLOCK ASSEMBLY

    OK

    GO TO ECM POWER SOURCE CIRCUIT (ENGINE CONTROL SYSTEM / SFI SYSTEM) Click here