Quick answer
If central locking has stopped working completely, start by checking the key fob battery, spare key, car battery voltage and central locking fuse. If only one door is affected, a failed lock actuator, latch fault or door wiring issue is more likely.
Because locking faults affect security and access, recurring issues are worth fixing promptly. A door that will not latch, unlock or open correctly should not be ignored.
What central locking faults look like in real life
Remote does nothing
Often points to key fob battery, remote signal, pairing issue, fuse or low car battery voltage.
Key fob not working →Only one door fails
Usually points towards that door’s actuator, latch, wiring loom or connector.
Door will not open inside →Locks click but do not move
A weak actuator, sticky lock mechanism or voltage issue may be stopping full movement.
Works sometimes
Intermittent faults often come from weak batteries, wiring breaks, loose connectors or failing actuators.
Started after flat battery
Low voltage can upset remote locking, alarm, windows and body control systems.
Battery keeps going flat →Alarm behaves oddly
Alarm, immobiliser or body control issues may appear alongside central locking faults.
Common reasons central locking stops working
Flat key fob battery
A weak remote battery is one of the simplest and most common causes.
Weak car battery
Low voltage can upset locks, alarms, windows, mirrors and other body electronics.
Check battery health →Blown fuse
A failed fuse can disable the locking circuit or part of the body control system.
Door actuator fault
If one door will not lock or unlock, the actuator may have failed or become weak.
Door wiring damage
Repeated door opening can damage wires near hinges or inside the rubber boot.
Sticky latch mechanism
Dirt, corrosion or wear can stop the latch moving freely even when the actuator works.
Water ingress
Moisture inside doors can damage connectors, lock motors and wiring.
Aftermarket alarm or tracker
Poor wiring or faulty accessories can interfere with locking and battery drain.
Control module fault
Less common, but body control modules can fail, lose communication or need diagnosis.
Helpful clues that narrow it down
- 1All doors affected: key fob, car battery, fuse, receiver or control module fault more likely.
- 2Only one door affected: actuator, latch, linkage, wiring or connector likely.
- 3Works with key but not remote: key fob battery, remote pairing or receiver issue possible.
- 4Locks click but do not move: weak actuator, sticky latch or low voltage possible.
- 5Started after flat battery: battery weakness, low voltage reset or module issue possible.
- 6Intermittent problem: broken wiring, loose connector or failing actuator may be developing.
- 7Door will not open: treat it as an access and safety issue, not just a convenience fault.
- 8Alarm goes off randomly: locking, bonnet switch, door switch or alarm fault may be linked.
What to check first
1. Try the spare key
This helps separate a key fob problem from a vehicle locking problem.
2. Replace the key fob battery
Use the correct battery type and check the remote buttons are not damaged.
3. Check car battery health
Weak voltage can cause multiple electrical faults, especially in cold weather.
4. Test each door
Check whether the fault affects one door, several doors, boot lock or fuel flap.
5. Listen for clicking noises
A click without movement often points towards actuator or latch resistance.
6. Check fuses carefully
Use the vehicle handbook or fuse box diagram. Do not replace fuses with incorrect ratings.
One door vs all doors fault
One door not working
Usually points to that door’s actuator, latch, cable, linkage, wiring loom or connector. If the door also will not open from inside or outside, the latch may need urgent attention.
All doors not working
More likely linked to the key fob, receiver, fuse, body control module, alarm system or weak vehicle battery.
Boot lock only
Can be a boot latch, wiring loom, water ingress, broken switch or actuator fault.
Fuel flap does not unlock
Some cars lock the fuel flap through central locking, so a flap actuator fault can appear separately.
Remote key works badly or only close to the car
If the remote only works close to the vehicle, works after several presses, or stops working in cold weather, the key fob battery is the first thing to check. If a new fob battery does not help, the key buttons, circuit board, receiver or vehicle battery may need diagnosis.
- ✓Try the spare key before buying expensive parts.
- ✓Replace the remote battery with the correct type.
- ✓Check whether the manual key still locks and unlocks the door.
- ✓Check whether the car battery is weak or repeatedly going flat.
- ✓Do not ignore water damage, cracked buttons or loose key casing.
Related guide: car key fob not working.
Can you still drive with central locking not working?
Usually yes, if the doors latch securely and can be opened safely. But the vehicle may be easier to steal, harder to access, or inconvenient if the fault gets worse.
Do not drive normally if a door will not latch shut, opens unexpectedly, cannot be opened in an emergency, or traps passengers inside. That is a safety issue, not just a locking issue.
Typical UK repair costs
Key fob battery
Usually low cost and quick to replace.
Key repair or coding
Varies by key type, programming needs and whether a spare key exists.
Door actuator repair
Moderate cost depending on door trim access and part price.
Fuse or simple wiring
Can be lower cost if the fault is easy to find and access.
Door wiring loom
Cost varies depending on broken wires, connector condition and labour time.
Module diagnosis
Can vary widely because electrical testing time is the main cost.
Accurate diagnosis often saves money compared with replacing random actuators, keys or modules.
Central locking checks when buying a used car
Central locking faults are easy to miss during a quick viewing. Test every door, boot, fuel flap and both keys before buying.
- ✓Check both key fobs lock and unlock the car.
- ✓Check each door from inside and outside.
- ✓Check the boot, fuel flap and alarm behaviour.
- ✓Listen for weak clicking or slow lock movement.
- ✓Ask whether a spare key is included.
- ✓Be cautious if the seller says it is “just a battery” but has not fixed it.
Before buying, read used car inspection checklist, questions to ask when buying a used car and used car test drive checklist.
Related ownership, battery and electrical guides
Frequently asked questions
Why has my central locking stopped working?
Flat key fob batteries, weak car batteries, blown fuses, actuator faults, wiring damage and control module issues are common causes.
Why does only one door fail to lock?
Usually because that door has a failed actuator, sticky latch, broken linkage, damaged connector or broken wiring in the door loom.
Can a weak battery cause central locking faults?
Yes. Low car battery voltage can cause strange locking, alarm, window and body-electrical problems.
Can I lock the car manually?
Often yes, depending on the vehicle and which part has failed. Check the handbook for emergency locking instructions.
Will central locking fix itself?
Usually no. Intermittent actuator, wiring or voltage faults often become more frequent over time.
Why does the lock click but not move?
A weak actuator, sticky latch, poor voltage or mechanical resistance inside the door may be stopping movement.
Should I replace the key fob first?
Not straight away. Try the spare key and replace the fob battery first before paying for a new key.
Best first step?
Try the spare key, replace the fob battery, check the car battery and identify whether one door or all doors are affected.