RETROFIT : BMW E91 - Tempomat (Cruise control)

There are several variants of cruise control. This is the DIY about simplest option of cruise control, ie. maintain desired speed without braking function and no matter of distance of the vehicle in front of you (Active Cruise Control).




Cruise control is available for use at speeds of approx. 20 mph or 30 km/h. The car then memorizes
and maintains the speed that you specify using the lever on the steering column.

1  Storing and maintaining speed or accelerating

2  Storing and maintaining speed or decelerating

3  Deactivating cruise control

4  Resuming a speed stored beforehand



After you press the lever, arrow 1, or pull it,
arrow 2, at a driving speed of more than approx.
20 mph or 30 km/h, the speed at which you are currently driving will be stored and maintained.
It is displayed in the speedometer and briefly in the instrument cluster.




For this retrofit you will need two parts:
1. Steering column switch cluster (SZL)











The functions of the steering column switch cluster are:
  • Detecting switching signals in the steering column switches
  • Detecting steering angle and steering speed
  • Detecting the controls in the multifunction steering wheel
  • Sending and receiving information to/from the interlinked control units

If you don't have rain/light sensor you can freely buy switch cluster with automatic wipers, it will work as the one with manual wipers. And if you decide to retrofit rain/light sensor you will have auto wipers ready.
 
2. Lower steering column cover











Installation:

First thing to do is to disconnect the negative pole of battery. This is necessary because it is possible to accidentally activate airbag and risk serious injury !!!

Next, remove the airbag using something like torx screwdriver (T20 for example :) ):

Under the wheel, on both sides, there is a hole.

Put the torx screwdriver inside this hole at the right angle and move it to the left, for the hole on the right, and to the right for the hole on the left.

Next picture show how does it looks on the inside of the steering wheel with airbag removed.








Airbag connection to the steering wheel is made by the two pins fitted in two holes (showed at the center of the picture on the left).

Steel wire is what holds these pins in place. You have to move it right (for left hole) and to the left (for the right hole).




Before you remove the airbag, disconnect the airbag connector.
Here you can remove the connector for the multifunctional switches on the steering wheel.








To remove the steering wheel you have to remove the hex bolt with screwdriver. Then gently pull the wheel toward yourself.








Next thing to do is to remove the upper cover and the leather cover.









Then, remove the lower cover.










Before you remove the switch cluster, first disconnect the connectors behind the switch cluster located on the right side.
6-pin connector (3) is for the airbag and you can remove it quite easy.
12-pin connector (2) is been used for all the functions that switch cluster provides.









To remove the connector, press the black part, then, holding that part pressed, move the white plastic to the right (as shown on the picture). This is a common type of the connector in BMW vehicles and probably in automotive industry and the way to remove it :)

The connector will slightly move outward, then just pull it out.

After removing connectors, unscrew four torx screw and remove switch cluster.




















You can buy used switch cluster with or without coil spring:









If you got one without this part, don't worry, you can use your old one. You just need to detach few clips and remove it from the switch cluster.
The sole purpose of the coil spring is to pass the connection from the multifunctional switches on the steering wheel down to the switch cluster and the airbag connection to the rest of the system (bypassing the switch cluster).

When you mount new  switch cluster, assembly procedure is straightforward. Just follow pictures in reverse order ;)

Coding:

When done, you need to code the car, ie. tell the car you have extra equipment. As soon as you connect the battery and turn the ignition on you'll get several errors, but don't be scared, that's normal condition where coding is necessary.
The electronic steering column switch cluster module contains a processor, the power supply and following interfaces:
   • F-CAN
   • Optical switches
   • Electrical switches
The steering column switch cluster SZL consists of several components where the steering angle sensor is one of the most important. The steering angle sensor detects the steering angle setting of the steering wheel and is evaluated in the SZL. The information is mainly required by the DSC control unit. That's why we have errors related with DSC.
The steering column switch cluster must detect the steering angle and steering speed information as the basis for calculating various functions in the DSC. Further information such as the absolute steering angle or the steering wheel rotation information is calculated. A steering angle of -180°/+180° is detected.

You can do coding using NCS Expert and adding option $540 to Vehicle Order (VO), write it to modules that holds VO (FRM and CAS in my car) and code the whole car.
Important note: SZL communicates via F-CAN bus to the DSC and further via the PT-CAN to the DME/DDE. In other wods, for SZL, DSC acts as a gateway to the rest of the system. The steering column switch cluster cannot be addressed directly via the BMW diagnosis system. So, DSC module must be encoded after replacing the steering column switch cluster. The DSC transfers the coding to the steering column switch cluster.
That's why you can't find SZL module shown in UIF (User Information Field) in INPA, or in NCS Expert among other modules in E9X cars (in E60, SZL can be accessed directly).
If you get DSC module coded with errors, something is wrong with your SZL.

After coding, errors are still present. Next thing to do is to calibrate steering angle sensor. You can do it easy way: turn ignition on, turn the wheel all the way left, then, turn the wheel all the way right. That procedure should calibrate steering angle sensor.
Calibration can be done in DIS that will instruct you to do the same thing as above procedure. If there are still errors in your car, you can erase error memory in INPA, and that would be all.

Some cars can experience working cruise control, but not showing it on intrument cluster. You can turn it manually by changing following option in KOMBI module:

TEMPOMAT_SETZ_ANZ_DAUER     - wert01 change to wert02

You should have now fully working cruise control ;)

5 коментара:

  1. Thank you for perfect explanation :)
    Can you please explain can the coding be done with kd can cable and NCS expert and do I need power backup for this?
    Thank you

    ОдговориИзбриши
  2. Nice one lad! Done mine last weekend and have been loving it ever since.
    Thanks for posting this in such good details.

    ОдговориИзбриши
  3. What about 4cyl and 6cyl diesel cars? Is the cc stalk swappable between these 2 engines?

    ОдговориИзбриши
  4. My car e91 LCI dont show the popup in kombi after retrofit tempomat .
    what could be wrong ???? (tempomat dauer in kombi is set to wert 02

    plz help

    ОдговориИзбриши