how to diagnose a Honda Civic 9th Generation (2012-2015) that won’t start

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, flathead screwdriver, and safety glasses.
• Safety Warnings: Disconnect the battery before working on electrical systems.

2. Battery Service

1. Disconnect Battery: Use a wrench to remove the negative terminal first, followed by the positive terminal.
2. Clean Terminals: Use a wire brush to clean any corrosion from battery terminals and cable ends.
3. Reconnect Battery: Reconnect the positive terminal first, then the negative terminal.

3. Starter Relay Replacement

1. Access Fuse Box: Open the fuse box cover located under the dashboard or hood.
2. Locate Starter Relay: Identify the starter relay based on the diagram inside the fuse box cover.
3. Remove Relay: Pull the relay out gently using pliers if necessary.
4. Install New Relay: Insert the new starter relay into the same slot securely.

4. Ignition Switch Testing

1. Remove Ignition Switch Cover: Use a screwdriver to remove screws and take off the cover.
2. Check Continuity: Using a multimeter, check the continuity of the ignition switch when turned to the "Start" position.
3. Replace Ignition Switch: If faulty, disconnect the wiring harness and remove the ignition switch. Install a new ignition switch and reconnect the wiring harness.