Central locking is no longer working.

The remote locking had just stopped working on my trailblazer. I have two sets of remotes and neither of them are working with the car currently. It was totally random just came back from a trip and it wouldn't lock but had been fine the rest of that day. I have tried re-programming the remotes to the car as I was t sure if the dog standing on the door button may have caused it to disconnect somehow however this doesn't work and I have today tried replacing the remote batteries and trying to reprogam again but this hasn't worked either. The doors were locking/unlocking with the but
Experienced mechanics share their insights in answering this question :
It sounds like your vehicle has a problem with the body control module, mainly because you said the power locks are also inoperative from the door panel. The first thing I would suggest is to check the fuses, then have the body control module scanned. This might give you a fault code to work with or to help diagnose the issue. It may simply be a blown fuse. Beyond that, not much can be done without a test light, wiring schematic, and a good working knowledge of automotive electrical systems. At that point, I would recommend having the locking problem diagnosed by a professional technician.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

A faulty central locking system might be due to several reasons, such as a blown fuse, faulty solenoid, or electrical wiring issues. Also, it`s good to remember the fault might not be with the central car locking system but the key fob instead; over time, fobs require battery changes.
The Power Locks Don`t Work

A problem with one lock is probably due to the lock actuator or another malfunction inside the mechanism of the door itself. But if none of the power locks work, check the fuse box in your vehicle. A blown fuse can cause the power locks to stop working.

If the locks on all doors suddenly stop working or responding, the key fob may be to blame. A dead battery or a malfunction may prevent the fob from sending a signal; in this case, the key fob may need to be reprogrammed or replaced.
This turns out to be one of the most common reasons for a car lock to stop working. In this case, all you have to do is replace the key fob battery. However, if changing the battery doesn`t help, the key fob may be faulty and you should contact the dealer for further key fob tests.
A door locking motor is fitted to each door and connected to a control box located under the fascia in front of the steering wheel. A 20 amp fuse is incorporated to protect the System, see figure 1.
A blown fuse prevents power transfer to the actuator, thus disabling the lock system.
The door locks are electronically controlled, and as is the case with many other automotive electrical circuits, they will run their power through a relay. The door lock relay is the relay responsible for sending power to the door lock actuators so that they can lock and unlock the vehicle.
A blown fuse is the common hurdle in locking doors properly. Car doors rely on this fuse`s command to lock or unlock. The fuse is usually located under the glove box (passenger`s side) and can get blown due to high voltage. The fuse is cheaper and can be easily replaced at home.
If your ECU controls the anti-theft system, disconnecting the battery may lock you out of your car. Like desktop computers and most other electronics, disconnecting the battery cable for a short period will not fully reset your ECU due to the residual power remaining in the circuits.
Door control module: The door control module or the master window switch is what typically controls the functions of the windows and the door locks. It receives any signals from the remote related to door locks or window functions.
The majority of cars now have remote central locking, however, with a flat or dead battery this won`t work and you will be forced to use the key to open the car doors.
The latching mechanism in a vehicle is installed directly in its doors. It contains both a latch and an electric motor (actuator) which controls the central locking. The latch opens or closes the doors, whereas the door lock locks or unlocks the vehicle. Today, all door latches are powered by electric drives.
If a fuse blows, or the relay fails, your ABS will stop working. You will still have your standard braking system, but the ABS will no longer deliver the pulses to the brakes that prevent you from sliding or locking up.
Fuse lockouts and blockouts are highly visible devices that feature a unique locking mechanism that prevents the device from being accidentally removed from a fuse block. They will help you comply with OSHA`s lockout tagout standard.
The hinges may be worn down from regular wear and tear, damaged by corrosion, or even warped or dented from an impact of some kind. If the hinges look a little rusty or clogged with dirt, you can try cleaning them off with WD-40 and other cleaning supplies.
Lockout relays are used by many utilities in electrical power transmission substations to trip and hold out of service a protection zone on the occurrence of a relay operation that requires inspection and/or repair before the zone may be safely placed back in service.
Locks that are part of larger security often draws power from the security system itself, though some of these locks may operate using a battery as a backup power source. Most electronic keypad locks are designed so that disabling their power source does not open them, without power the locks remain locked.
These actuators are controlled by the central locking system and/or the remote control. Each actuator`s motor operates a lifter that activates and deactivates the lock. Additionally, the lifter may be retained by a latch mechanism and used specifically for anti-theft protection.
The majority of cars now have remote central locking, however, with a flat or dead battery this won`t work and you will be forced to use the key to open the car doors.
Fix 1: Make Sure Auto Lock is Enabled on Your iPhone

On your iPhone, launch the Settings and tap on Display & Brightness followed by Auto-Lock. On the screen that follows, you will find multiple time durations for the Auto Lock feature. Tap on the one that you think is suitable for you and the feature will be enabled.

The majority of cars now have remote central locking, however, with a flat or dead battery this won`t work and you will be forced to use the key to open the car doors.
If your ECU controls the anti-theft system, disconnecting the battery may lock you out of your car. Like desktop computers and most other electronics, disconnecting the battery cable for a short period will not fully reset your ECU due to the residual power remaining in the circuits.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Automatic locks do not work properly.
ANSWER : Hi there. When the locks look as if they are trying to move but do not, it’s typically due to a fault with the primary module or relay that powers the door locks. There are many different components that make up the power lock system, so before you attempt to remove or replace the module, you might want to have a professional mobile mechanic complete a power door locks are not working inspection.

Driver side door lock button not working, and passenger side sliding door makes a buzzing noise
ANSWER : Hi there. These door issues are common on this vehicle. Most of the time the main issue is the master door lock switch on the driver door. It sounds like you already replaced that. As for the sliding door problem, most of the time, this is a failure within the door module or it can be a connection issue.

I typically take the door apart and check the connections on the module and inside of the door just to make sure that there is nothing apparent in there. If the connections and the wiring are fine, then I use a scan tool to check the module to see what the inputs and outputs are doing. If you need to have this looked at, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose your door problem and recommend a repair.

Wireless key have good batteries, central lock work very good but suddenly the two wireless keys stop working 2006 Toyota RAV4
ANSWER : Hi there – if both of the known good keys stop working, it is likely the key transceiver in the vehicle has stopped working for some reason. Check for blown fuses, just in case. The Toyota security system software (next level of detail beyond OBD II) MAY indicate the failure point, but may not. For assistance, I recommend a electrical component inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.

Front Passenger Lock sometimes does not lock with a remote control or by locking button located on either doors.
ANSWER : The solenoid is on the door latch and is most likely the cause of the problem for your 2005 Toyota Tacoma. If you want to have this inspected and repaired, a certified technician from YourMechanic can come to your home or office to diagnose your door lock and perform the correct replacement.

all doors lock only by inserting key in passenger side door and locking
ANSWER : Your central locking system may have been designed with a control module in the circuit. This is a small computer that is responsible for controlling the different functions of a particular system. It is possible that the module for your central locking system may have shorted out internally preventing particular functions from working properly. I would recommend having a certified technician test your central locking module to determine if all of its functions are working properly.

Driver and Passenger doors won’t lock, but I hear them click and see the locks twitch.
ANSWER : If the same problem is happening even when you use the inside door lock switch then the most likely cause of the locks not moving is going to be weak actuators. You should replace the drivers lock actuator first since it is used the most and you will see it fixes the problem. Then you can replace the other doors as needed.

Central locking is no longer working.
ANSWER : It sounds like your vehicle has a problem with the body control module, mainly because you said the power locks are also inoperative from the door panel. The first thing I would suggest is to check the fuses, then have the body control module scanned. This might give you a fault code to work with or to help diagnose the issue. It may simply be a blown fuse. Beyond that, not much can be done without a test light, wiring schematic, and a good working knowledge of automotive electrical systems. At that point, I would recommend having the locking problem diagnosed by a professional technician.

Windshield wipers stopped working. They’ll suddenly stop working then suddenly start working again. Has been happening for a week.
ANSWER : The problem you are describing likely stems from an intermittent electrical fault in the wiper circuit. The windshield wiper system uses a small electric motor to move the wiper arms that you see on the windshield. That electric motor is controlled through a switch, relay, fuse, and wiring. One, or more, of those electrical components has failed although it is also possible that the mechanical arms are binding (seized, if the lubricant has dried out) thus causing the electric circuit to the motor to overload. Regardless of the underlying fault, if you request a non functioning wiper diagnostic/repair, the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.