Why Won’t My Key Fob Open My Car? Possible Reasons Why

Reviewed by

Anthony Harlin, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on November 4th, 2023

Reading Time: 3 minutes
Summary
  • If your vehicle won’t lock or unlock with your key fob, it can be a great inconvenience.
  • Possible reasons your car won’t unlock with your key fob include key fob battery problems, key fob damage, and faulty wiring or a blown fuse.
  • A damaged door lock actuator or latch can also cause issues connected to your key fob not opening your car.

You might be wondering “why is my vehicle’s auto-lock not working?” Having a car that won’t lock or unlock is a perplexing and frustrating issue. Modern vehicles have advanced features like keyless entry, but they can still be susceptible to car doors that won’t lock or unlock if the key fob or the locking system fail.

Why Won’t My Car Unlock With a Remote or Key?

Let’s delve into the possible causes of this problem and see if there are ways to quickly resolve the issue.

Key Fob Battery Problems

If your key fob functions intermittently or has lost all functionality, then its battery could have died. Aside from preventing you from unlocking your vehicle, your car also won’t lock with the key fob.

An old battery can cause the fob to work intermittently or produce a signal that is too weak to cover long distances, while a dead battery can cause it to not work at all. Sometimes, the key fob leads might not be making proper contact with the battery, which will also cause the fob to not work.

You can diagnose whether your key fob has this issue by replacing the battery. If it still refuses to function, then you might need a signal reader to determine if the key fob is still working.

The Key Fob Is Damaged

If you’ve ruled out a dead battery, then the key fob itself could be broken. If you take the fob to your car dealer, they can connect it to a computer and check whether it needs to be reprogrammed. Deprogramming can sometimes occur if the buttons are accidentally pressed in a specific sequence.

Most key fobs are shockproof, but they can still break when dropped repeatedly. If dropped at waist level, most fobs will probably be able to withstand the impact. However, they might crack if you leave them in your pocket and sit on them for an extended period.

Additionally, key fobs are also not waterproof. If they’re dropped in water or get soaked, their internal components are most likely damaged.

The key fob’s buttons can also stop functioning because of damage or wear. Many key fobs have buttons made of rubber, which can become brittle and tear after years of use.

Faulty Wiring or Blown Fuse

There are times when the problem might lie with the wiring of the locking system. For example, a faulty wire or a blown fuse can block power from reaching the door lock actuators or the key fob’s receiver.

When reassembling the panels on a door or dashboard, a mechanic or other professional might inadvertently disconnect a wire. This might have happened if you recently disassembled your vehicle to repair its door latches or when you inspected the onboard computer.

Damaged Door Lock Actuator or Latch

The door lock actuator is a tiny motor that locks or unlocks the doors. If it fails, you won’t be able to lock or unlock your doors with the key fob.

A damaged door lock actuator can be caused by water damage or everyday wear and tear. If water enters the electrical system, it can corrode and short out various components in your car’s central locking system, including the door lock actuator.

The door lock assembly can also jam. This can cause a car door lock to become caught in the locked position, preventing the key fob from unlocking the doors. When this occurs, pulling on the door hinge from the inside won’t be possible either. 

This can happen because your vehicle’s door latch can break. While the chances of this happening are slim, it can cause a car door lock to become caught in the locked position, preventing the door from opening. You might hear your door lock assembly move, but your door won’t open.

If your car won’t unlock with the key fob, just remember that it isn’t always the key fob’s fault. A faulty door lock or door lock ajar switch can also prevent your key fob from locking or unlocking your vehicle. Sometimes it also can be your vehicle’s wiring, door latches, or the key fob receiver. If you find yourself locked out of your vehicle, then you should reach out to your local locksmith.

About The Authors
Reviewed By Anthony Harlin, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Tony Harlin is a Master Gas and Diesel Diagnostic Technician with over 18 years of experience. He works full-time at a large independent automotive shop as a driveability and repair technician working on all types of vehicles with a focus on diesels. ASE certifications include A1-A9, L1 and L2, as well as X1.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

Share
Published by
CarParts.com Research Team and Anthony Harlin, ASE Certified Master Automobile Technician
Tags: key-fob