It can be a big problem when you go out to your car and it won’t lock or unlock. You may be tempted to call a locksmith or a dealer but there are some simple fixes you should try before you spend money on a service call.
Some of the reasons why car won’t lock or unlock include the battery in the key fob is dead, a blown fuse, a key fob malfunction, or a solenoid issue. The rod or connection could be faulty or you could have electrical problems.
The rest of the article explains how you identify exactly which is is your problem.
Bad Key Fob Battery
The most common reason why your car won’t lock or unlock is a bad key fob battery. You will know this is the issue if none of the doors lock or unlock.
Key fob batteries are easily replaced by picking up a button battery at a local discount store. All you have to do is open up your remote by sliding a flathead screwdriver into the bottom slot and part the outer case and then replace the battery and close it again.
Read: Why Car Won’t Detect Key Fob?
Sometimes a blown fuse will create a locking problem. You will know this is the case if all but one door doesn’t work.
Replacing the fuse is also easy to do. The fuse box is located under the dash near the steering wheel in most cars. They are numbers and correspond with a diagram explaining what they control in the car owner’s manual.
Once you find the correct fuse, all you have to do is remove and replace it. Most cars even have extra fuses located in the fuse box.
Read: Why Car Key Won’t Come Out?
Key Fob Malfunction
Replacing the battery may not fix the problem. That’s when it’s apparent you’re facing a key fob malfunction. There are terminals or other components in the fob that could be bad.
Unfortunately, you won’t be able to determine this yourself. You will need to take your fob to a car deader and have them connect it to a commuter to check it. Fobs that don’t send a signal will need to be replaced.
Replacement fobs can cost anywhere from $150 up to $500. Expensive cars are going to have more expensive fobs because of all the security measures associated with those high-end fobs.
Read: TROUBLESHOOTING CAR’S ELECTRICAL SYSTEM
Those that have replaced the key fob battery, the fuse, and had their fobs cleared as working by a computer at the dealer could have a bad solenoid. The door lock solenoid is located in the door.
A symptom of this problem is if only one door doesn’t work. While replacing the solenoid isn’t a complicated procedure, it is a bit hard to get to because the door panel will need to be removed.
Broken Rod or Connector
One of the rarer problems affecting door locks is that a rod or some of the plastic connectors broke. These items link door panel switches with all the handles and locks. Plastic can break over time.
It could also be that dirt and junk have, over time, seeped into the door panel through the window being opened and closed repeatedly. Fixing a rod or connectors is about as tedious as a solenoid replacement. The door panel will need to be removed for your mechanic to diagnose and fix.
However, a mechanic will be able to see the problem immediately once they remove the door panel so no computer diagnostics are required.
The final, and least common, problem affecting a car’s locking mechanisms is electrical problems. A symptom of this is either a faulty logic board or something going on with the wiring, such as a break, a short, or burned wiring.
Sometimes, the wire’s plastic insulation is worn and that can cause issues.
You will know this is the problem if your car lock works sometimes and doesn’t work other times. A wire could be broken if none of the car locks work at all and you’ve replaced the battery.
Use the Key
All cars, even the push-button starts, have a physical key that will lock and unlock the car. The key is typically hidden in the key fob or came as a backup for the car. Use that until you figure out the problem or have a mechanic look at the situation.
Why will my car unlock but not lock?
This is probably a malfunctioning fob where the relay isn’t working. Check to see if you can feel either the unlock or lock functions click when you press them It is a bad relay you can feel the unlock function but not the lock function.
It could also be a wiring issue.
Why won’t my door locks work after I changed out my battery?
You just need to reset everything when you reconnect the battery. Remove the negative battery cable (the black one) from the battery and place it against the positive one (red) for 30 seconds. Be careful of sparks.
The entire network, including nodes and capacitors, will power down. Reconnect the negative battery to the negative terminal.
Why won’t my locks work or my car start?
Non-working locks and a car starting issue could be one issue or two separate issues. The one issue could be the battery on the car needs recharging. There are times a dead battery can affect door locks, although it really shouldn’t have any effect on locks.
It is likely the reason the car won’t start though. Jumpstart the battery and see what happens.Your door lock issue could be separate in that a dead key fob battery may be causing that issue.
Replace it and see if your locks work.
Why will my fob unlock my doors but not start my car?
The problem lies with either your car battery or a bad key. Nothing is wrong with your fob but a dead car battery will prevent it from starting. You will need to jumpstart the car.
Once it’s got some power through the jumper cables, try using the keyfob “start” button to see if the fob works. Those with a push-start may try to press the start button with the keyfob close by.
Use the hidden key to try to start the car if neither of those options works. You have a problem with the fob if the key works to start the car.
Read: How Long Can a Car Battery Sit Unused?
How do I start a push-start car if the key fob is dying?
A key fob that needs a battery replacement may still be able to start your car. Place the fob at the base of the steering column and press the start button. Use the hidden key in the fob if that doesn’t work until you can get a new battery.
Why does my car say “key not in range?”
This error code on a car usually means the battery in your key fob needs to be replaced.
Do I need to reset my key fob?
There may come a type when you will need to reset your key fob. Fobs are like other devices in that they can go quirky, lose the signal or just stop working. Sometimes, this happens after you replace a car battery.
You can reprogram your key fob yourself. All cars have a process for reprogramming the fob that involves turning the key to the alternator position, back off, and back on again, among other things.
Your car owner’s manual will have the exact procedure for reprogramming the fob for your make and model of car.