käiguvahetuslülitil

Käiguvahetuslüliti, often translated as a shift interlock or gear shift interlock, is a safety mechanism found in vehicles with automatic transmissions. Its primary function is to prevent the driver from accidentally shifting the transmission out of Park or Neutral without first depressing the brake pedal. This prevents the vehicle from lurching forward or backward unexpectedly when the transmission is engaged, thus enhancing safety.

The operation of a käiguvahetuslüliti typically involves a solenoid or a mechanical linkage that is connected to the brake pedal. When the brake pedal is pressed, this connection is activated, allowing the gear selector to be moved from the Park position. If the brake pedal is not pressed, the mechanism is engaged, physically preventing the shifter from moving out of Park. Some systems also require the ignition to be in the "on" position for the interlock to disengage.

Variations of the käiguvahetuslüliti exist. Older or simpler systems might rely on purely mechanical connections. More modern vehicles often incorporate electronic controls, where sensors detect brake pedal application and signal the transmission control module to release the interlock. Regardless of the specific implementation, the core purpose remains the same: to ensure that the vehicle is stationary and the driver has firm control before selecting a driving gear. This safety feature is a crucial component in modern automatic transmission systems.