SFI SYSTEM (w/ Electronic Throttle Control 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

A0136C5E01

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (EFI FUSE - ECM, EFI FUSE - BATTERY)


    1. A0138JPE04

      Disconnect the ECM connector.

    2. Remove the engine room relay block.

    3. Remove the engine room relay block lower cover.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      B26-22 (BATT) - 1C-4 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B26-22 (BATT) or 1C-4 - Body ground Always 10 kΩ or higher

    5. Reinstall the engine room relay block.

    6. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    CHECK AND REPLACE ENGINE ROOM RELAY BLOCK