Pt.1 BMW F series Cruise Control Retrofit

Posted by techmanager 27/02/2018 0 Comment(s)

Clearly, we at ProCarDiag aren't the only ones who love these kind of projects! And what's not to love? DIY projects are a win across the board -- they can save money, express creativity and are just plain fun.

What does this DIY project do?
Replace and code multifunction steering-wheel switch from LIM function to dynamic cruise control capability on BMW F20 or F30. This will allow the car to have dynamic cruise control capability. The set speed can be selected from 30 km/h to 180 km/h: in convenient steps of 10 or fine steps of 1. The set speed is displayed on the instrument panel via speedo dial and briefly on information display. 

Dynamic Cruise Control

Dynamic cruise control is an electronic cruise control system with an extra braking function. This also includes the Curve Speed Limiter that reduces the speed in curves for comfortable lateral acceleration. At the end of the curve the car accelerates and resumes the original speed. The driver can change this in increments of 1 or 10 km/h. Acceleration and deceleration in two dynamic settings can be controlled by manipulating the lever on the steering. 

Brief component description: Multifunction steering-wheel switch

The multifunction steering wheel contains a horn switch and airbag plus, depending on the model, buttons for controlling the radio, telephone and cruise control. The buttons are split between 2 switch blocks; left and right.

Functional description

The left multifunction steering wheel switch block is directly connected to the right one via a plug connection. This means that all the button signals in the left multifunction steering wheel switch block are detected and digitised in the electronics of the right switch block.
The right multifunction steering wheel switch block sends the signals via the local interconnect network bus to the steering column switch cluster. The steering column switch cluster is the data interface between the local interconnect network bus and FlexRay. All button signals are sent as FlexRay messages.
The right multifunction steering wheel switch block is directly connected to the left one via a ribbon cable. 

Index Explanation Index Explanation

Switch cluster, multifunction steering wheel, right 


Left-hand multifunction steering wheel switch cluster 


The whole multifunction steering wheel 


Rocker switch + 


Toggle switch - 


Hands-free mode button 


Telephone button 


Knurled wheel for selection list (e.g. selecting the radio station) 


MODE button 
Toggle button, e.g. between audio sources 


Rocker switch to increase or decrease driving speed 


Button I/0 
Switch cruise control to stand-by or off button


Reset button
Resume or load saved speed button 


Set button 13
Button to set the desired driving speed 

But what is really this DIY?

This DIY will guide you on how to change/code the multifunction steering-wheel switch with cruise control function. The BMW can be either F20/F30 series with automatic air condition. 

Required parts:
BMW OEM Multi steering-wheel switch
Note the difference in the trim piece highlighted by
*orange* arrow. 

*this is a leather steering wheel (it can be sport leather steering wheel also)

Required tools:

1.Flat head screw driver
2.Torx screwdriver T10, T20 
3.OBD/Ethernet cable 
4.ESD strap
5.Wrench 10mm
Computer with esys installed