Cruise control with braking function (LDM)

Functional description, see BMW Service Technology:

TIS -> Document -> SI Technology -> SBT Number 66 03 04 086

Note:

In the E90\E91\E92, there are up to three various cruise control systems:

• Cruise control SA 540
  (set speed is maintained by the engine)
  
• Cruise control with braking function SA 544
  (set speed in addition to SA 540 is also implemented or maintained by brake activation via the DSC)
  
• Active cruise control (ACC) SA 541
  (contains the functionality of SA 544 and additional distance control via the ACC sensor)
  

LDM control module:

With optional extra 544 (up to 09/06) and optional extra 541 in the E90/E91/E92, the scope of functions of the software for cruise control is implemented in a separate control module: the LDM control module.

As of 09/06 or on the E92 with the beginning of series production (06/06), the cruise control with braking function (optional extra 544) is integrated in the DSC control module. The LDM control module is therefore eliminated on optional extra 544 as of 09/06.

A precondition for the function is that the engine / transmission control and the DSC are operating without faults.