ECD SYSTEM(for Swirl Control Valve) ECM Power Source Circuit

DTC Code DTC Name
ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, the battery voltage is applied to the IGSW terminal of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the EFI MAIN relay coil, closing the EFI MAIN relay contacts and supplying power to terminal +B, +B2 and +B3 of the ECM.

WIRING DIAGRAM

A321033E05

CAUTION / NOTICE / HINT

Note:

  • When replacing the ECM, the ECM needs Registration and Initialization (Click here).

  • Inspection the fuses for circuits related to this system before performing the following inspection procedure.

Tip:

When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the GTS. Then after installing the new ECM, perform all of the initialization/registrations for the "Learning Values Write" function by following the instructions shown on the tester display.

PROCEDURE

  1. CHECK HARNESS AND CONNECTOR (POWER SOURCE)

    U184653E02

    1. Remove the No. 1 integration relay from the engine room No. 1 relay block.

    2. Remove the EFI MAIN relay from the engine room No. 1 relay block.

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      1C-1 - Body ground

      Always

      11 to 14 V

      5 (EFI MAIN relay holder) - Body ground*1

      3 (EFI MAIN relay holder) - Body ground*2

      Always

      11 to 14 V

      • *1: for LHD

      • *2: for RHD

      Table 1. Text in Illustration

      *1

      Engine Room No. 1 Relay Block

      *2

      EFI MAIN Relay

      *a

      Front view of wire harness connector

      (to No. 1 Integration Relay)

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      1A-2 - Body ground

      Always

      Below 1 Ω

      1 (EFI MAIN relay holder) - Body ground

      Always

      Below 1 Ω

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK - BATTERY)

  2. INSPECT NO. 1 INTEGRATION RELAY (IG2)

    1. Inspect the No. 1 integration relay (IG2) (Click hereClick here).

    REPLACE NO. 1 INTEGRATION RELAY

  3. INSPECT EFI MAIN RELAY

    1. Inspect the EFI MAIN relay (Click hereClick here).

    REPLACE EFI MAIN RELAY

  4. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK - ECM)

    1. Disconnect the ECM connector.

    2. Remove the EFI MAIN relay from the engine room No. 1 relay block.

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

      Standard Resistance (for LHD)

      Tester Connection

      Condition

      Specified Condition

      A76-9 (MREL) - 2 (EFI MAIN relay holder)

      Always

      Below 1 Ω

      A76-2 (+B) - 3 (EFI MAIN relay holder)

      Always

      Below 1 Ω

      A76-14 (+B2) - 3 (EFI MAIN relay holder)

      Always

      Below 1 Ω

      A76-1 (+B3) - 3 (EFI MAIN relay holder)

      Always

      Below 1 Ω

      A76-9 (MREL) or 2 (EFI MAIN relay holder) - Body ground

      Always

      10 kΩ or higher

      A76-2 (+B) or 3 (EFI MAIN relay holder) - Body ground

      Always

      10 kΩ or higher

      A76-14 (+B2) or 3 (EFI MAIN relay holder) - Body ground

      Always

      10 kΩ or higher

      A76-1 (+B3) or 3 (EFI MAIN relay holder) - Body ground

      Always

      10 kΩ or higher

      Standard Resistance (for RHD)

      Tester Connection

      Condition

      Specified Condition

      A76-9 (MREL) - 2 (EFI MAIN relay holder)

      Always

      Below 1 Ω

      A76-2 (+B) - 5 (EFI MAIN relay holder)

      Always

      Below 1 Ω

      A76-14 (+B2) - 5 (EFI MAIN relay holder)

      Always

      Below 1 Ω

      A76-1 (+B3) - 5 (EFI MAIN relay holder)

      Always

      Below 1 Ω

      A76-9 (MREL) or 2 (EFI MAIN relay holder) - Body ground

      Always

      10 kΩ or higher

      A76-2 (+B) or 5 (EFI MAIN relay holder) - Body ground

      Always

      10 kΩ or higher

      A76-14 (+B2) or 5 (EFI MAIN relay holder) - Body ground

      Always

      10 kΩ or higher

      A76-1 (+B3) or 5 (EFI MAIN relay holder) - Body ground

      Always

      10 kΩ or higher

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  5. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)

    1. U121927E02

      Disconnect the ECM connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A76-4 (E1) - Body ground

      Always

      Below 1 Ω

      A76-5 (E2) - Body ground

      Always

      Below 1 Ω

      A76-17 (E3) - Body ground

      Always

      Below 1 Ω

      A76-18 (E4) - Body ground

      Always

      Below 1 Ω
      Table 2. Text in Illustration

      *a

      Front view of wire harness connector

      (to ECM)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. CHECK HARNESS AND CONNECTOR (IGSW TERMINAL VOLTAGE)

    U121926E02

    1. Disconnect the ECM 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

      A76-37 (IGSW) - Body ground

      Ignition switch ON

      11 to 14 V
      Table 3. Text in Illustration

      *a

      Front view of wire harness connector

      (to ECM)

    REPLACE ECM

    (Click here)

  7. CHECK HARNESS AND CONNECTOR (ECM - NO. 1 INTEGRATION RELAY)

    1. Disconnect the ECM connector.

    2. Remove the No. 1 integration relay from the engine room No. 1 relay block.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A76-37 (IGSW) - 1A-4

      Always

      Below 1 Ω

      A76-37 (IGSW) or 1A-4 - Body ground

      Always

      10 kΩ or higher
    Table 4. Result

    Result

    Proceed to

    NG

    A

    OK (w/ Entry and Start System)

    B

    OK (w/o Entry and Start System)

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    CHECK HARNESS AND CONNECTOR (IGNITION SWITCH ASSEMBLY - NO. 1 INTEGRATION RELAY)Click here

  8. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - NO. 1 INTEGRATION RELAY)

    1. Disconnect the power management control ECU connector.

    2. Remove the No. 1 integration relay from the engine room No. 1 relay block.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H70-8 (IG2D) - 1A-3

      Always

      Below 1 Ω

      H70-8 (IG2D) or 1A-3 - Body ground

      Always

      10 kΩ or higher

    GO TO ENTRY AND START SYSTEM

    (Click here)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  9. CHECK HARNESS AND CONNECTOR (IGNITION SWITCH ASSEMBLY - NO. 1 INTEGRATION RELAY)

    1. Disconnect the ignition switch assembly connector.

    2. Remove the No. 1 integration relay from the engine room No. 1 relay block.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H6-6 (IG2) - 1A-3

      Always

      Below 1 Ω

      H6-6 (IG2) or 1A-3 - Body ground

      Always

      10 kΩ or higher

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  10. INSPECT IGNITION SWITCH ASSEMBLY

    1. Inspect the ignition switch assembly (Click here).

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION SWITCH ASSEMBLY - BATTERY)

    REPLACE IGNITION SWITCH ASSEMBLY

    (Click here)