Key fob doesn't lock, unlock, or start the car

Symptoms

• No response when pressing fob buttons
• Fob works only when very close to the car
• Push-button start doesn't recognize the fob
• Fob light or feedback doesn't activate when pressed

Likely causes

• CommonDead or weak fob batteryThe small coin battery inside wears out over 1–3 years typically.
• CommonFob out of range or interferenceMetal objects, other electronics, or distance can block the signal.
• PossibleFob needs reprogramming or resetFobs can lose sync with the car after a dead 12V battery or certain repairs.
• PossibleCar's receiver antenna issueA problem with the car's own receiving hardware can prevent fob recognition.
• PossibleFob physically damagedDropping or water exposure can damage the internal circuit board.

What to do

1. Replace the fob's battery (usually a small coin cell, model listed in the owner's manual).
2. Try the fob very close to the car, sometimes even touching the door handle or start button, to rule out weak signal.
3. Test if the physical key (hidden inside most fobs) can manually unlock the door.
4. For push-button start cars, check the manual for a spot to hold the fob against if the battery is dead (often near the start button).
5. If a second fob works fine, the problem is likely isolated to the one fob's battery or internal fault.
6. If no fobs work, check the car battery too, since a weak 12V battery can affect the receiver.
7. Have a dealer or locksmith reprogram the fob if a battery change doesn't fix it.
8. Replace the fob entirely if it's been dropped, gotten wet, or is several years old and unreliable.

Tools and parts

• Small screwdriver
• Coin cell battery (correct size)

When to call a pro

A dealer or locksmith is usually needed to program a brand new fob to work with your specific car's security system.

Safety