Window lifters

Depreciation

Window lifters in new vehicles are reliable products. Should a fault occur, it usually affects the mechanics, which can be replaced separately from the engine.

Function

Most modern vehicles feature electric window lifters (power windows) alongside manual lifters. Electric window lifters are controlled using buttons in door trim panels. For central control, there is usually a panel featuring buttons for all electric window lifters in the vehicle in the driver's door. Occasionally there are also controls located in the centre console.

Electric window lifters on more recent vehicles are fitted with what are known as convenience functions. These include:

• Automatic full up or down of the window lifter when the switch is pressed once
   
• Linking of the window lifter function to the central locking so that when the car is locked, all of the windows that were previously open close automatically.
   
• Safety functions such as "anti-trap protection"

Safety

"Anti-trap protection" is the most important safety function in a window lifter system. It ensures that neither objects nor body parts can become trapped between door frame and window when a window is closing. In more basic systems, this is implemented using mechanical means with a slip or friction clutch. Electronic window lifters with comfort closing in particular are fitted with a more complex safety function. When a resistance is registered during closing, the movement of the window is reversed automatically so that it opens immediately. An electronics unit which is attached directly to the engine and detects any resistance due to a trapped object usually takes care of this function.