What Is Speed Sensing Auto Door Lock? Feature Explained

What Is Speed Sensing Auto Door Lock?

Speed Sensing Auto Door Lock is a safety and convenience feature that automatically locks all the doors of a vehicle once it reaches a predetermined speed. This system aims to prevent accidental opening of doors while the vehicle is in motion, particularly beneficial for child safety and overall security.  

How Does Speed Sensing Auto Door Lock Work?

The system relies on the vehicle’s speedometer sensor and the central control unit (Body Control Module or BCM). Here’s a typical operational sequence:  

1. Speed monitoring: The speedometer sensor continuously monitors the vehicle’s speed.
2. Threshold detection: The central control unit is programmed with a specific speed threshold (typically around 10-20kmph).
3. Lock activation signal: Once the vehicle’s speed exceeds this pre-set threshold, the control unit sends a signal to the door lock actuators.
4. Automatic locking: The door lock actuators engage, automatically locking all the doors of the vehicle.

Conversely, the system is often programmed to automatically unlock the doors when one of the following occurs:

• Vehicle stops: When the vehicle’s speed drops to zero.
• Ignition is turned off: When the driver turns off the engine.  
• Driver’s door is opened (sometimes): In some implementations, unlocking occurs when the driver’s door is opened after the vehicle has stopped.

What Are The Pros and Cons of Speed Sensing Auto Door Lock?

Here are the pros, or advantages, of speed sensing auto door lock:

• Enhanced child safety: Prevents children from accidentally opening the doors while the vehicle is moving, significantly reducing the risk of falls or other accidents.
• Increased security: Deters unauthorised entry into the vehicle while it’s in motion, especially in traffic or less secure areas.  
• Peace of mind: Provides drivers with a sense of security knowing that the doors are automatically locked once the vehicle starts moving.  
• Convenience: Eliminates the need for the driver or passengers to manually lock the doors after starting the journey.

Here are the cons, or disadvantages, of speed sensing auto door lock:

• Potential inconvenience for passengers: Passengers might find it slightly inconvenient if they need to exit the vehicle immediately after it stops, as they might need to wait for the automatic unlocking or manually unlock their doors.
• System malfunction: Although rare, a malfunction in the speed sensor or the central control unit could lead to the doors not locking automatically or unlocking unexpectedly.
• Emergency situations: In the event of an accident where the central locking system malfunctions due to electrical damage, occupants might face difficulty in opening the doors manually. However, modern cars usually have mechanical overrides for such situations.

Aftermarket Installation Of Speed Sensing Auto Door Lock In India

Installing Speed Sensing Auto Door Lock as an aftermarket feature is relatively common and generally more straightforward than complex safety systems like airbag deployment. Several aftermarket central locking systems and standalone modules offer this functionality.

• Availability: Many car accessory shops and online retailers in India offer aftermarket Speed Sensing Auto Door Lock systems.
• Cost: The cost of aftermarket systems can vary depending on the brand, features, and installation charges, typically ranging from a few thousand rupees to upwards of ₹10,000.
• Installation Complexity: Installation usually involves tapping into the vehicle’s speed sensor wire and connecting it to a control module that manages the door locks. While some experienced DIY enthusiasts might attempt it, professional installation by a qualified auto electrician is highly recommended to ensure proper wiring and functionality and to avoid potential electrical issues.

Verdict - Should You Get Aftermarket Speed Sensing Auto Door Lock?

Given the significant safety and convenience benefits, Speed Sensing Auto Door Lock is a highly recommended feature. If your vehicle doesn’t come equipped with it from the factory, installing a reliable aftermarket system by a qualified professional is a worthwhile investment, especially if you frequently travel with children or prioritise vehicle security. Ensure that the aftermarket system you choose has good reviews and comes with a warranty for added peace of mind.

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