W204 C250 Coupe Locks for Doors in 2011.

[ChatMaven]

Good day, everyone.

I am new to this forum and this is my first post. I kindly need assistance.

After doing extensive research on Google and several online forums, I have been unable to locate any instances that precisely match the situation I am now experiencing. When attempting to unlock the vehicle using the key fob, I have seen that both the driver and passenger doors open as anticipated, with the pins rising as predicted and the internal door mechanisms producing audible sounds. However, despite these indications, the car remains locked. When exerting force on both the driver and passenger door handles, it is seen that there is a lack of resistance, with the pins in an upward position indicating that the doors are still locked.
By using the key fob, I am able to replicate the act of locking or unlocking several times, resulting in occasional successful release of the locks. However, in the event that this method proves ineffective, I may resort to using the actual key from the key fob, which has shown to be successful.
I guess my queries are as follows:
Is it possible that the main battery is the cause? To the best of my knowledge, there has been no replacement for this feature, and the Start/Stop option has been unavailable for a number of years. Will the process include a complete removal of both doors in order to replace the whole actuator units?

Any assistance would be much appreciated.

[TDudette]

To start the process, it is advisable to apply a lubricant, such as silicone or GT85, into each crevice associated with lock mechanisms, as opposed to use WD-40.

[ChatMaven]

Thank you, I will absolutely attempt that since it is undeniably a more cost-effective alternative.

[Mistral]

The use of normal WD40 is not recommended since it has a tendency to accumulate residue rapidly.

[TDudette]

It is evident, my acquaintance.

[Mistral]

It is improbable that the issue lies with the battery; yet, it is worth noting that low voltage may manifest in many anomalous behaviors inside automotive systems. Do you own, or are you acquainted with someone who has, a battery conditioner or charger? Applying an electrical charge to the lock mechanism may potentially address the issue, and even if it does not resolve the problem with the lock, it might have a positive impact on the battery and overall functioning of the vehicle.

[ChatMaven]

Thank you everyone for your assistance. I have applied GT85 to both mechanisms, as per the advised approach. Initial testing has shown positive results. However, it is important to note that intermittent issues may arise, where the problem may not manifest for a period of one to two weeks, only to resurface with increased severity.
The document will be submitted for review on Friday, and I will request that they examine it thoroughly.
I express my gratitude one again.
 

[TDudette]

It is advisable to annually apply a protective spray to the locks and periodically rotate the emergency key, with particular attention given to the boot lock.

[ByteStorm]

Please inform us of the steps taken to address this issue. I am experiencing a similar intermittent problem with my 2012 S204, albeit just the driver's door is impacted.
The automatic locking feature has been disabled due to instances when the inside door handle failed to unlock the door.
However, it is worth noting that a manual key consistently functions well.