How to Reset a Loose or Missing Gas Cap

A missing gas cap may show a warning light on your dash.

If you do not fully tighten your gas cap or you forget to put it back on when you fill your gas tank, a light may flash on your dash that displays "Check Engine," "Gas Cap" or "Check Emissions." If this happens, you'll need to eventually reset the gas cap light.

Things You'll Need

• New gas cap (optional)

Instructions

1. Turn off your vehicle.

2. Purchase a replacement gas cap from your local dealership's parts department, if needed. If you still have the gas cap and did not loose it, forgo this step.

3. Thread the gas cap off the filler spout counterclockwise. Be careful, as one of the main reasons for the light to appear is a cross-threaded cap. The cap might not easily thread off the filler spout if this is the case.

4. Place the thread of the cap squarely on top of the filter tube and turn it clockwise until the cap makes a clicking sound. This ensures the cap is on tight and without cross-threading.

5. Turn on your vehicle. The light should not turn on. However, if the light remains on, drive the vehicle for 5 to 10 minutes to give the computer time to run a diagnostic to determine the gas cap is on correctly.

Tips & Warnings

• If you lost your gas cap, first call the gas station where you last filled your tank. Someone may have turned it in.

References

• "Honda Civic 2001-2010, CR-V 2002-2009 Repair Manual by Haynes"; Robert Maddox, John H. Haynes; 2010
• "Nissan Sentra, 200SX Repair Manual 1995-2006"; Larry Warren, Tim Imhoff, John H. Haynes; 2010