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.

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

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

Courtesy of AMERICAN HONDA MOTOR CO., INC.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Power Circuits

Use the Manual With the Right Hardware

When to See a Mechanic

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