[filipkozina]

Hello guys , I am working on BMW X6 E71 2008 3.5d..
Problem is with DSC , all lights on dash are on(4x4 , dsc , active steering,airbag,RPA,parking brake...) also WIPERS are on and no control over them.
I read errors with ISTA and there is a lot of "message problem" transmitter DSC reciver ICM , EMF , MRS, AFS..

The weirdest thing:

There is no communication with dsc UNTIL  I press the brake pedal , when I do that all dash lights are gone and no errors.
Also when fault lights are on AUTO Hold is lighted green , when I press brake light is off ... When I move steering wheel dash light and auto hold light are lighting on my movment (blinkning ).

What did I try: 
JBE replace
SZL replace
ICM replace
AFS replace
Checked all fuses 
Replace fuse box
Checked ground connectors in engine bay 
Replace brake light switch
Replace steering wheel angle
Checked FCan wires to DSC
(I didnt left any of this parts on car , I just test it because I have used car parts shop)

This problem firstly come when you steer to full stop and drive  and not always , now it is only good when you press brake pedal

Anyone did have this and know what is problem ??

[Node]

Most likely dead DSC. Or you may be lucky and try to reflash DSC firmware. Or you may also check if it receives 15WUP signal.

Wipers are also controlled by DSC. What a surprise, isn't it?

This is extract from ISTA:
Steering column switch cluster (SZL)
The SZL forms the interface between the wiper switch and the junction box electronics (JBE). The signals from the wiper switch are processed by the SZL and forwarded to the Dynamic Stability Control (DSC). The SZL sends its information via the F-CAN to the DSC.
Dynamic Stability Control (DSC)
The DSC processes the information from the SZL. The DSC forwards the requests from the SZL and the information regarding driving speed to the junction box electronics (JBE). The DSC is connected to the JBE via the PT-CAN.

[filipkozina]

I didnt write that I tried 2x DSC modules , all the same..

[Node]

Ok, if other DSCs are not helping then I would bet on 15WUP or F/PT-CAN wiring to DSC issue. But given that brake pedal is able to wake DSC up, its probably 15WUP. Maybe you should also check if all 3 voltage supply and 2 ground wires are ok.

Update: oh you checked F-CAN, so PT-CAN remains to be checked.

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And the usual source of 15WUP problems is IBS. Try to disconnect it first as a simplest check.

[filipkozina]

I did check with multimeter where is engine electronic 15wup to DSC it is good , did check PT-can to dsc it is also where is electronic and it have signal ...
On your advice I disconnect IBS there is no difference
I checked 3 voltage supply and 2 ground wires they are okey

does PT-can or F-can have some testing instructions or something special ? I tested wire and it is okey..

Any othere ideas?

[Node]

At this point I wonder if its correct DSC on that car. Did it just break as this? Do you know history of the car?

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There is a CAN-bus transmission control unit ABL in ISTA+. You may try that too.

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You can also measure voltages on all 4 F/PT-CAN low/high wires and report here. Can also try to measure them in AC mode with engine started to get an idea if signals are there. Of course if would happen to have an oscilloscope, that would be easiest way to test CAN signals.

[filipkozina]

The car was in crash , front end was destroyed , I make that car and car has been driving 3 years without problems, no errors , the problem started last month , nobody didn't change anything since I work on it..
I will measure and report , thank you for your help on this !

[eliasole]

If you have any fault with dsc sensor front or rear under car change it and you should be fine

[willisodhiambo]

Please post the errors from ISTA

It either a bus problem or a sensor problem, my hunch is that a message from DSC CAN is missing. Faulty sensor or loose connector pin.

[tonemoz]

Check the wiring harness in the drivers footwell area, I seem to remember a problem we saw before. I will try and find more details for you.