K-bus reset- professional help needed ***

So basically my car is MESSED up and I believe the K-BUS needs to be reset, there are a few threads here but nothing that has resolved my problem.
The car is a 2004 BMW 325i E46
Symptoms:
- Turn signals work on outside, not in cluster
- Cluster backlight doesn't work
- Cluster gauges DO WORK, RPM/SPEED/GAS/THERMOSTAT ALL WORK
- Windows dont work
- Wipers dont work
- Radio DISABLED
- Sunroof not working
- Side view mirrors DO WORK
- Trunk release from inside doesn't work
- Doors dont lock when i start driving
- Cluster doesn't show doors open when they are, and interior dome lights remain on after doors are closed.


I took it to a German Car Specialist and here is what the said word for word.

INSPECT INSTRUMENT CLUSTER AND PROGRAMMING
Labor - customer concern of loss of several convenience items, confirmed. Scanned vehicle for fault codes, found that the radio as well as many other modules have no communication. Consulted with Phil, recommends to inspect all fuses. Inspected both fuse block, the one in the glove compartment and in the trunk, all fuses are okay, inspected with test light. Will need further diagnosis. Fault in instrument cluster for K-line, and light switching centre internal fault, no communication with light switching center, central electronics, radio, with scan tool, code instrument cluster - instrument, fault did not change. Remove trim to access light switching center, disconnect light switching center, attempt to communicate with control modules- no change in communication. Windshield wipers also do not work.

They told me I need to pay another 400$ just for them to continue DIAGNOSTICS, not to fix it. Part of me wishes I went straight to the dealership. My dad is a fully licensed mechanic with over 25 years experience, it's just that from what i read on the forums there is a special software required for the reset, so if there is anything that can be done from home, it wont be a problem. SOME ONE PLEASE REACH OUT TO ME

If theres more info needed i will keep posted on this thread. Thanks in advance.

Well this is your lucky day, I diagnose these kinds of problems all day. Yes your K-bus is down, but there isn't really a reset. I have seen all sorts of things cause a K-bus to die. Some things I need to ask first, what year, transmission type, any wiz bang stereo stuff installed, has it rained where your at recently?
You basically have a white/red wire with yellow dots on it, this is your K-bus wire. All of your basic body modules talk on this wire. I have seen water in the left rear of the trunk cause a 3-pin connector to get wet and short the bus out. I have seen the phone wiring bundle under the armrest get coffee spilled in there and short the bus out.

So there is a god above me? lol First of all I am so glad you took the time to respond to me.

My car is a 2004 325i, manual transmission. The only thing installed to my radio is an auxillary cable which has been on the car for atleast 4-5 months now, without any problems. It hasn't rained here in a while just snow tho.

I will definitely have a look at those cables. Where else exactly can I look for this cable besides under the armrest and the side of the trunk?

Thanks again.

Check out a website called http://wds.spaghetticoder.org/en/ they have the wiring diagrams for your car.

So the K-bus wont need to be reset. When you remove the faulty module that is bringing it down it will start to work. You can see the actual bus activity if put a meter between the K-bus wire (white wire, red stripe, yellow dots) and ground. You might see no voltage or 12v depending on the fault, what you want to see is a data stream of voltage that will go all over the place. With a simple craftsman meter you can't see the data, with a scope you could see the data stream.

You can split the wiring in half if you disconnect a connector right behind the heater control panel, it is mounted to the actual heater box I believe the connector is white. You can access it by removing the little pocket under the heater control panel. If you disconnect this you separate the back half of the K-bus from the front, you should even see the small wire I described.
Let me know what this does.

@F1004fun

So we've definitly made some progress, we disconnected the connector behind the heater and everything kicked into gear, windows, wipers, cluster etc. but ofcourse the back end of the car (brake lights, turn signals) doesn't function with the disconnection. When I plugged it back in to see what would happen, the turn signals stopped working again etc. , altho the windows remained functionable. Anyways we then realized that the tail lights were still not working even after we re-connected the connector from behind the heater. My dad tested out a few things (I even bought a new battery) and what he thinks is that one of the relays are acting up. So yeah this is where I stand now.

Please get back to me, I will be waiting for your much appreciated response.

I had a mini cooper in my shop with a can bus problem. Sounds similar to your problem. Ended up being the OEM Ipod interface. Try disconnecting your auxiliary cable.

Well some thing isn't right. When you disconnect that plug on the heater you are disconnecting all of the entertainment systems from the body bus. This is the radio, phone pre-wire, nav pre-wire. This should have no effect on you lights. So with this disconnected you still don't have turn signals in the back but do you have the ticking noise in the dash. Get this, that ticking noise you hear when you hit the turn signal is actually a relay in the instrument cluster just to simulate the ticking noise, but this means the bus is good. Do you have lights in the front? Lighting output is not on the bus only light requests on the input side.