Manual door locks are a traditional automotive security system that requires the user to physically lock or unlock each door individually, using a mechanical key from the outside or a knob/lever/rod from the inside.

Description of Manual Door Locks

Mechanism: These systems use simple, direct mechanical linkages (rods and levers) connecting the interior lock knob, the interior and exterior door handles, and the exterior lock cylinder to the central door latch. When a key is inserted into the exterior lock cylinder and turned, or when the interior knob is pushed down/pulled up, these rods physically move the latch mechanism into a locked or unlocked position.

Operation: The driver or passenger must manually perform an action at each door to secure or unsecure the vehicle. This contrasts sharply with modern automatic or power door locks, which use electric actuators to lock/unlock all doors simultaneously via a central switch or a remote key fob.

Simplicity and Reliability: A key advantage of these traditional systems is their simplicity; they do not rely on electrical power or complex computer modules, making them highly reliable and less prone to expensive electronic failures.

Security Trade-offs: The primary drawback is a lower level of security and convenience compared to modern systems. Their simple mechanical nature historically made them easier to "jimmy" open or pick with simple tools.

Discontinuation and Modern Status

Manual door locks have largely been discontinued as standard equipment in the automotive industry, particularly in passenger cars and most modern vehicles, due to the widespread adoption of power locks and central locking systems.