How to get in and start your car with a dead key fob
The backup methods most cars use when the smart key battery is flat: the hidden metal key and the start button trick.
Getting in
- Look for a release button or slider on the fob. It frees a small metal key hidden inside.
- Find the keyhole on the driver's door. On many cars it hides under a small plastic cap at the end of the handle.
- Unlock the door with the metal key. The alarm may sound until the car detects the key inside.
Starting
Push-button start cars still detect a fob with a flat battery when it is held very close to a reader. Where that reader sits depends on the brand.
- Many cars want the fob held against the start button while you press the brake.
- Others have a marked slot or pocket in the centre console, cup holder or steering column.
- The owner's manual describes the exact spot. Our vehicle pages include it when the manual does.
Afterwards
Replace the battery soon. The backup method is meant for emergencies, and the metal key alone will not start most modern cars.
Find your exact battery
Each vehicle page lists the battery size, opening steps and the manual it came from.
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Last updated 2026-10-16. General advice; your owner's manual is the final word for your vehicle.