SFI SYSTEM ECM Back-up Power Source Circuit

DESCRIPTION

The battery supplies electricity to terminal BATT of the ECM even when the ignition switch is off. This electricity allows the ECM to store DTC histories, freeze frame data, fuel trim values and other data.

WIRING DIAGRAM

A01VJ8YE01

CAUTION / NOTICE / HINT

Note


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

  • Perform electronic throttle learning after replacing the ECM Click here.

  • After turning ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work Click here.

PROCEDURE


  1. INSPECT BATTERY


    1. Check that the battery is not depleted.

      OK
      Battery is not depleted.

    NG

    REPLACE BATTERY

    OK

  2. CHECK BATTERY TERMINAL


    1. Check that the battery terminals are not loose or corroded Click here.

      OK
      Battery terminals are not loose or corroded.

    NG

    REPAIR OR REPLACE BATTERY TERMINAL

    OK

  3. INSPECT NO. 1 INTEGRATION RELAY


    1. A01VE7HE06
      Text in Illustration
      *a

      Compartment without harness connected

      (No. 1 Integration Relay)

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1C-1 - 1E-9 Always Below 1 Ω

    NG

    REPLACE NO. 1 INTEGRATION RELAY Click here

    OK

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


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

    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
      1E-9 - A71-22 (BATT) Always Below 1 Ω
      1E-9 or A71-22 (BATT) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - BATTERY)


    1. Disconnect the negative battery terminal.

    2. Disconnect the positive battery terminal.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1C-1 - Battery positive terminal Always Below 1 Ω
      1C-1 or Battery positive terminal - Body ground Always 10 kΩ or higher

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR