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Power Circuits

  1. Check for battery voltage between ECM power terminal and ground. See POWER & GROUND CIRCUITS TERMINAL IDENTIFICATION  table. See Fig 1 . If battery voltage does not exist, check appropriate ECM fuse in underhood fuse box. See ECM POWER CIRCUITS FUSE IDENTIFICATION  table. If fuse is okay, check for an open in wire between underhood fuse box and appropriate ECM power circuit terminal.
  2. Turn ignition on. Check for battery voltage between appropriate ECM power circuit terminal and ground. See POWER & GROUND CIRCUITS TERMINAL IDENTIFICATION  table. If battery voltage does not exist, check appropriate fuse in underhood fuse box. See ECM POWER CIRCUITS FUSE IDENTIFICATION  table. If fuse is okay, check for an open in wire between fuse box and appropriate ECM power circuit terminal and check for a defective ignition switch.
    POWER & GROUND CIRCUITS TERMINAL IDENTIFICATION

    Application (1) ECM Terminal
    Ground Circuits A23, A24, A26 & B2
    Power Circuits
    Ignition Switch In OFF Position D1
    Ignition Switch In ON Position A25 & B1
    (1) For terminal location, see Fig 1 .
    ECM POWER CIRCUITS FUSE IDENTIFICATION

    Application Fuse
    Accord, Civic & Civic Del Sol
    Ignition Switch In OFF Position BACK-UP
    Ignition Switch In ON Position ECM
    Prelude
    Ignition Switch In OFF Position CLOCK
    Ignition Switch In ON Position BACK-UP
    Fig 1: Identifying ECM Terminals
    G93I79051Courtesy of AMERICAN HONDA MOTOR CO., INC.