my Honda Civic 10th Generation (2016-2021) won't start but the lights work

Solution

1. Preparation

• Gather tools and parts required.
• Ensure the vehicle is parked on a level surface with the engine off.
• Disconnect the negative battery terminal to prevent any electrical shorts.

2. Battery Inspection and Replacement

• Inspect Battery Terminals

  • Remove the battery terminal covers.
  • Clean any corrosion using a wire brush or baking soda solution.
  • Tighten the connections securely.

• Battery Testing

  • Use a multimeter to verify battery voltage.
  • If voltage is below 12.4 volts, proceed to replace the battery.

• Battery Replacement

  • Remove the battery hold-down brackets using a socket set.
  • Carefully lift the battery out of the tray (may require assistance due to weight).
  • Install the new battery in reverse order, ensuring terminals are connected correctly (positive first, then negative).

3. Starter and Relay Inspection

• Starter Relay Check

  • Locate the relay in the fuse box (consult owner's manual for exact location).
  • Remove the starter relay and inspect for signs of damage.
  • Swap with a similar relay to test functionality.

• Starter Motor Testing

  • If the relay is functional, locate the starter motor.
  • Check wiring for loose connections or damage.
  • Use a multimeter to test for voltage at the starter when the key is turned to the start position.

4. Fuel System Check

• Fuel Pump Functionality

  • Turn the ignition to the "ON" position without starting the engine.
  • Listen for the fuel pump's priming sound from the fuel tank.

• Fuel Pressure Testing

  • Connect a fuel pressure gauge to the fuel rail test port.
  • Turn the ignition to the "ON" position and check the pressure reading against manufacturer specifications.