Retractable Hardtop: Notes

A retractable hardtop is being used on the new BMW 3-Series E93 convertible for the first time. The three-part roof construction has been manufacture from sheet steel plate using the lightweight construction method. The roof opens in approx. 22 seconds and closes in approx. 23 seconds.

The retractable hardtop provides the following advantages:

A high degree of on-road comfort with the roof closed with increased suitability for daily use
Good all-round view with the roof closed on account of the narrow C-pillar as well as large rear window
Opening and closing with a total height of 170 centimeters, which means it is also possible in garages

Fig 1: Identifying Retractable Hardtop

Courtesy of BMW OF NORTH AMERICA, INC.

A central hydraulic unit drives the retractable hardtop, The sequence of movements is supported by 8 hydraulic cylinders. 6 gas-pressurized props are also involved in the sequence of movements. The hydraulic unit is activated by the Convertible Top Module (CTM). A total of 14 sensors (from 07/2012 15 sensors) monitor the sequence of movements.

NOTE: Additional sensor from 07/2012!

An additional sensor has been introduced for monitoring the position of the hardtop: Hall effect sensor left 'Roof package stored'

IMPORTANT: Emergency backup operation exclusively for service use!

Emergency activation of the retractable hardtop for the customer is not implemented. However, emergency actuation is possible in Service. The emergency activation is described in detail in the repair instructions .