AUTOMATIC TRANSAXLE SYSTEM ECU Power Source Circuit

DESCRIPTION

When the engine switch is turned to on (IG), 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

A019JOZE01

INSPECTION PROCEDURE

PROCEDURE


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


    1. A019NPEE30
      Text in Illustration
      *1

      Front view of wire harness connector

      (to TCM)

      Turn the engine switch off.

    2. Disconnect the TCM connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D2-8 (E1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT ECU TERMINAL VOLTAGE (+B TERMINAL)


    1. A019NPEE31
      Text in Illustration
      *1

      Front view of wire harness connector

      (to TCM)

      Disconnect the TCM connectors.

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      D2-18 (+B) - Body ground Engine switch on (IG) 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 engine switch off.

    2. Disconnect the TCM connector.

    3. Remove the EFI MAIN relay from the engine room relay block.

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

      A019JP5E01
      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      D2-18 (+B) - 3 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      D2-18 (+B) or 3 - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1

      Front view of wire harness connector

      (to TCM)
      *2 Engine Room Relay Block Assembly
      *3 EFI MAIN Relay

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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