Body, doors & windows

Key fob won't lock or unlock the doors

A key fob that suddenly stops working usually just needs a new battery, but it can also point to a fob that's lost its programming, a receiver problem in the car, or interference from something nearby.

Difficulty
Easy
Time
10–20 minutes
DIY cost
$5–$15
Pro cost
$50–$150 for reprogramming

Symptoms

  • Pressing the fob buttons does nothing
  • No chirp, flash of lights, or click from the car
  • May work only when very close to the car, or not at all
  • Other functions like remote start (if equipped) also fail

Likely causes

  • CommonDead or weak fob batteryThese small batteries typically last one to several years and are the most common cause.
  • PossibleFob needs reprogramming/resyncingA dropped fob, a dead 12V battery event, or electrical work can sometimes desync a fob.
  • PossibleFailing door lock receiver module in the carThe car's receiver for the fob signal can fail independent of the fob itself.
  • Less commonRadio interferenceStrong nearby radio signals can occasionally interfere with a fob's signal.

What to do

  1. Try the fob very close to the door (within a foot or two) to rule out a battery that's just weak rather than fully dead.
  2. Replace the fob's battery with the correct type, available at most hardware and battery stores.
  3. Try a spare fob if you have one, to see if the problem is fob-specific or car-specific.
  4. Check that keyless entry hasn't been disabled in a vehicle settings menu, if your car has one.
  5. If a fresh battery doesn't help, look up your vehicle's fob reprogramming or resync procedure, which is sometimes simple enough to do yourself.
  6. Have a dealer or locksmith reprogram or diagnose the fob and receiver if the above doesn't resolve it.

Tools and parts

  • Small screwdriver (to open the fob)
  • Replacement fob battery
Key fob batterySearch: “key fob battery for [year make model] remote”

When to call a pro

A dealer or automotive locksmith can reprogram a fob or diagnose the car's receiver if a new battery doesn't solve it.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.