Door and Gate Locks Stopped Synchronising? What Happened?

Your digital door lock and gate lock used to unlock together with one authentication.

Now, only one lock responds.

The door and gate locks may still work individually, but the synchronised unlocking function has suddenly stopped.

Does this mean both locks are faulty?

Not necessarily.

Door-and-gate synchronisation depends on several separate conditions:

• Both locks must have sufficient power
• Both locks must remain correctly paired
• The synchronisation modules must remain connected and functional
• The first lock must successfully authenticate the user
• The second lock must be mechanically able to unlock

If any one of these conditions changes, the locks may stop unlocking together even though they still work normally on their own.

Jump to a Section

• How door-and-gate synchronisation works
• Wi-Fi and synchronisation are different
• Common synchronisation-failure symptoms
• Why synchronisation may stop working
• What it means when both locks work individually
• Synchronisation failure or mechanical problem?
• Troubleshooting steps
• When the module may be faulty
• How to reduce future problems
• Frequently asked questions

---

How Does Door-and-Gate Lock Synchronisation Work?

A synchronised lock system allows one successful authentication to trigger two compatible locks.

The usual process is:

1. The user presents a registered fingerprint, face, palm, PIN or card.
2. The first lock verifies the user.
3. The first lock begins unlocking.
4. Its synchronisation module sends a local instruction.
5. The paired lock receives the instruction.
6. The second lock begins unlocking without another authentication.

The two locks do not need to be one physical device. They communicate through compatible synchronisation modules.

For the system to continue working, the modules must:

• Remain correctly paired
• Receive sufficient power
• Maintain their internal connections
• Remain within a suitable communication distance
• Continue functioning electronically

Synchronisation Is a Separate Feature

A digital lock can continue functioning normally even when synchronisation has stopped.

For example:

• The door lock may still recognise fingerprints
• The gate lock may still accept a PIN
• Both locks may still unlock separately
• The app may still display both devices

The failed function may be only the communication between the two locks.

---

Wi-Fi and Door-to-Gate Synchronisation Are Different

A common misunderstanding is that synchronisation depends on the home Wi-Fi network.

In systems that use a dedicated local synchronisation connection, Wi-Fi and lock-to-lock communication serve different purposes.

• Wi-Fi connectivity allows supported locks to connect to an app, router or online service.
• Local synchronisation allows the compatible door and gate locks to communicate directly with each other.

This means a lock may appear offline in the app while the door-and-gate synchronisation still works.

It also means that restoring the Wi-Fi connection may not restore synchronisation when the actual problem involves pairing or the internal module.

What If the Home Internet Is Down?

Local synchronisation may continue without internet access, depending on the system design.

Both locks must still:

• Have battery power
• Remain paired
• Have functioning synchronisation modules

---

Signs That Door-and-Gate Synchronisation Has Failed

Common symptoms include:

• The first lock unlocks but the paired lock does nothing
• Both locks work separately but no longer unlock together
• Synchronisation works intermittently
• The second lock responds only after several attempts
• The locks stopped synchronising after a battery change or reset
• The synchronisation setting is missing
• Re-pairing works temporarily and then fails again
• The second lock makes a sound but cannot complete the unlock

These symptoms do not all have the same cause.

The first troubleshooting step is to determine whether the second lock:

• Received no command at all
• Received the command but lacked power
• Received the command but could not move mechanically

---

Why Did the Door and Gate Locks Stop Synchronising?

1. One of the Lock Batteries Is Low

Both locks require sufficient power.

The first lock may recognise a fingerprint and unlock, while the second lock may not have enough stable power to receive the instruction and operate its motor.

A low battery can sometimes affect connected or synchronised functions before the lock becomes completely unresponsive.

Check both locks rather than only the lock where the user authenticates.

2. One Battery Is Completely Flat

A lock without power cannot receive and complete a synchronisation instruction.

The powered lock may continue working normally, but the depleted lock will need to be powered through the emergency method supported by that model.

This may include:

• A USB emergency-power port
• External emergency-power contacts
• A mechanical emergency key

The available method varies by lock model.

3. The Synchronisation Pairing Has Been Removed

The locks must remain paired for the communication to work.

Pairing may be removed after:

• A factory reset
• A settings reset
• Lock servicing
• Replacement of an internal component
• Changes to the administrator settings
• Accidental removal of the synchronisation record

If both locks work individually but no longer trigger each other, remove the old synchronisation setting and add the pairing again.

4. The Synchronisation Module or Connection Has Become Loose

Digital door and gate locks experience repeated movement every day.

Over time, frequent forceful closing or slamming may expose the lock body and internal components to repeated vibration and impact.

In rare cases, this may contribute to:

• A loose internal connection
• A synchronisation module moving from its position
• Intermittent module contact
• Communication working only occasionally

This is not expected during normal controlled use, but it can occur after long-term repeated impact.

5. The Synchronisation Module Has Failed

An electronic module can eventually develop a fault.

Possible signs include:

• Both locks work normally on their own
• Both batteries are sufficiently charged
• Re-pairing does not restore synchronisation
• A factory reset does not solve the problem
• Synchronisation returns after the module or related lock component is replaced

When these conditions are present, the synchronisation hardware may require professional assessment.

6. The Locks Are No Longer Correctly Configured

A configuration change may affect which lock sends or receives the synchronisation command.

This can occur after:

• Administrator changes
• User-setting changes
• A lock reset
• Reinstallation
• Internal servicing

The correct synchronisation procedure should be followed for the specific lock combination.

7. One Lock Is Mechanically Unable to Unlock

The synchronisation signal may be working, but the second lock may be unable to complete the movement.

This may happen when:

• The door or gate is pressing against the bolt
• The strike is misaligned
• The gate has bounced out of position
• The locking mechanism is obstructed
• The motor is working against excessive resistance

In this situation, the problem is not necessarily the synchronisation connection.

8. Door or Gate Movement Has Changed

A door or gate may sag, shift or rebound after closing.

The second lock may receive the unlock command but struggle because the entrance is placing pressure against the bolt.

Look for:

• Long motor sounds
• Repeated unlock attempts
• Scraping near the strike
• The lock succeeding only when the door is pushed or pulled

9. Distance or Obstruction Has Changed

Local synchronisation is designed for compatible locks installed within a suitable door-to-gate distance.

Communication may be affected if:

• The lock position was changed
• A metal plate was added
• The entrance was modified
• The module position changed during servicing
• An additional obstruction was installed between the locks

Normal changes to home Wi-Fi do not necessarily affect local synchronisation, but physical changes around the modules may.

---

What Does It Mean When Both Locks Work Individually?

This is an important diagnostic clue.

If:

• The door lock recognises users and unlocks normally
• The gate lock recognises users and unlocks normally
• Both locks have sufficient battery power
• Only the combined unlock has stopped

Then the problem is more likely related to:

• The synchronisation pairing
• The sender or receiver module
• An internal connection
• The synchronisation configuration

It is less likely to be a complete failure of both locks.

What If Only One Lock Works Individually?

Resolve the individual lock problem before troubleshooting synchronisation.

For example:

• A flat battery must be recharged or replaced
• A misaligned bolt must be corrected
• A failed fingerprint does not trigger an unlock instruction
• A lock motor problem must be assessed

Synchronisation cannot make a non-functioning lock operate normally.

---

Is It a Synchronisation Failure or a Mechanical Problem?

The sound and movement of the second lock can provide useful clues.

The Second Lock Does Nothing

Possible causes include:

• Low or dead battery
• Lost pairing
• A loose internal module connection
• A failed synchronisation module

The Second Lock Makes a Sound but Does Not Unlock

This suggests that the command may have reached the lock.

The remaining issue may involve:

• Pressure against the bolt
• Door or gate misalignment
• A blocked strike opening
• Motor resistance

The Second Lock Works When the Door or Gate Is Open

If the lock responds normally while the entrance is open but fails while closed, alignment or bolt pressure is likely contributing.

The Second Lock Responds Only Sometimes

Intermittent behaviour may be caused by:

• A low battery
• Loose internal contact
• Door or gate movement
• An inconsistent pairing or module fault

Record several attempts rather than relying on one successful or failed test.

---

How to Troubleshoot Door-and-Gate Lock Synchronisation

Step 1: Test Each Lock Individually

Unlock the door and gate separately using their own registered access methods.

Confirm that:

• Both locks recognise the user
• Both motors operate normally
• Both bolts move smoothly
• Neither lock displays a separate error

Step 2: Check Both Battery Levels

Check the battery level of the door lock and gate lock.

If either battery is low:

• Fully charge the approved rechargeable battery pack, or
• Replace the full battery set where applicable

Test the synchronisation again after both locks have sufficient power.

Step 3: Observe the Second Lock

After authenticating at the first lock, check whether the second lock:

• Does nothing
• Makes a confirmation sound
• Activates its motor
• Retries several times
• Shows an error

This helps separate communication failure from mechanical resistance.

Step 4: Test with the Door or Gate Open

Where safe and appropriate, test the locks while the door or gate is open.

If the second lock responds while open but not while closed, inspect the alignment and bolt pressure.

Keep fingers away from moving bolts and strike openings.

Step 5: Remove the Existing Synchronisation

Open the lock settings and remove the current door-and-gate synchronisation connection.

Follow the correct procedure for the specific lock combination.

Step 6: Add the Synchronisation Again

Pair the compatible door and gate locks again.

After pairing, conduct several tests rather than relying on one successful unlock.

Step 7: Restart the Locks Where Appropriate

Follow the lock’s approved restart procedure.

Avoid performing an unnecessary factory reset because this may remove administrators, users and other settings.

Step 8: Do Not Assume a Factory Reset Will Fix a Hardware Fault

A factory reset may restore settings, but it cannot repair:

• A loose internal connection
• A damaged module
• A failed electronic component
• A mechanical alignment problem

If resetting and re-pairing do not help, further assessment is needed.

Step 9: Contact the Lock Supplier

Approach the lock supplier when:

• Both locks work individually
• Both batteries are sufficiently charged
• Re-pairing does not restore synchronisation
• The second lock remains completely unresponsive
• The problem repeatedly returns

---

When Might the Synchronisation Module Be Faulty?

A module or internal connection may require assessment when:

• Both locks work normally by themselves
• Both batteries have sufficient power
• The synchronisation pairing has been added correctly
• Re-pairing does not restore the connection
• The second lock receives no synchronisation response
• The problem is intermittent after repeated door or gate impact
• A factory reset does not resolve the issue

What May Need to Be Checked?

A technician may inspect:

• The synchronisation settings
• The transmitter and receiver modules
• The internal wiring or connectors
• The rear lock assembly containing the module
• The battery contacts
• The position of the module inside the lock
• The lock hardware and alignment

What If Replacing the Module Restores Synchronisation?

If resetting and re-pairing do not work, but replacing the relevant module or lock assembly restores synchronisation, the issue was likely related to the original module or its internal connection.

This does not necessarily mean that the entire lock had failed.

The main lock functions may have remained operational while only the synchronisation component stopped communicating.

---

What Can a Technician Do?

Depending on the diagnosis, a technician may:

• Confirm that both locks operate normally
• Check the battery condition
• Remove and restore the synchronisation pairing
• Inspect the internal module connection
• Reseat a loose connector
• Replace a faulty synchronisation module
• Replace the affected lock assembly where necessary
• Check the bolt and strike alignment
• Test repeated synchronised unlock attempts

The correct repair depends on whether the problem is caused by settings, power, internal communication or mechanical resistance.

---

How to Reduce Future Synchronisation Problems

• Avoid repeatedly slamming the door or gate
• Close the entrance with controlled force
• Keep both batteries sufficiently charged
• Respond to low-battery warnings promptly
• Do not factory-reset the locks unnecessarily
• Record the administrator and synchronisation settings
• Check alignment when a lock begins making repeated motor sounds
• Arrange an assessment if the synchronisation becomes intermittent
• Do not repeatedly force a lock that is struggling mechanically

Repeated impact does not always cause a synchronisation fault, but controlled closing reduces unnecessary stress on the lock, module and internal connections.

---

Frequently Asked Questions

Why did my door and gate locks suddenly stop unlocking together?

Possible causes include low battery power, lost pairing, a loose internal connection, a faulty synchronisation module or mechanical resistance at one of the locks.

Will the locks still work separately?

They may. If the synchronisation connection alone has failed, both locks can continue working individually using their own registered access methods.

Does synchronisation require Wi-Fi?

Not necessarily. Systems using local lock-to-lock communication may continue synchronising without home Wi-Fi or internet access.

Will synchronisation work if one lock is offline in the app?

It may, provided the offline status affects only Wi-Fi and both locks still have power, remain paired and have functioning synchronisation modules.

Will synchronisation work if one battery is flat?

No. A lock without power cannot receive and complete the synchronisation instruction.

Can low battery power affect synchronisation?

Yes. A lock may still light up or recognise a user while having insufficient stable power for communication and motor operation.

Why does the second lock make a sound but not unlock?

The synchronisation command may have reached the lock, but bolt pressure, misalignment or another mechanical obstruction may be preventing it from completing the unlock.

Should I factory-reset both locks?

Not as the first step. Begin by checking both batteries and re-adding the synchronisation pairing. A factory reset may remove administrators and user records without correcting a hardware fault.

Can slamming the door or gate affect the synchronisation module?

Repeated strong impact may expose the internal components to additional vibration. In rare cases, a module or internal connection may become loose after extended use.

Why did re-pairing not solve the problem?

If pairing is correct but communication does not return, the module, connector or related hardware may require professional assessment.

Can the synchronisation module be replaced without replacing the entire lock?

This depends on the lock design. Some systems use replaceable modules or rear assemblies, while others may require replacement of a larger component.

How can I tell whether it is a module problem?

A module issue becomes more likely when both locks work individually, both batteries are sufficient, the pairing is correct and software resets do not restore synchronisation.

---

Need Help with Door-and-Gate Lock Synchronisation?

Begin by checking whether both locks work individually and whether both batteries have sufficient power.

Next, remove the existing synchronisation pairing and add it again using the correct procedure.

If the second lock still does not respond, observe whether it is completely silent or attempting to move. This helps separate communication failure from mechanical resistance.

Synchronisation behaviour varies according to the lock system, battery condition, pairing, installation distance, module condition, internal connections and mechanical alignment. A local synchronisation connection can fail even when both locks continue operating individually.