K-Bus help!!
 

Can anyone tell me where the K-Bus is in the rear of the vehicle?? I have functions that are not working in the instrument cluster, and I have been told that it is the K-Bus. Where should I start?? I took the back end apart last night and the turn signal started working then quit again. I need guidance please.

Todder

The telephone (or prewiring for it), the amp, the ehc height control module (if equipped) are all in the back and on the K-bus.

I can scan the bus charts after work, but am out of time this morning...

Did you by any chance get any water in the back, like in the rear left corner? (can happen if the sunroof drains get clogged/unhooked)

Thanks Weasel, I would greatly appreciate that. No water, but I did put in a new stereo and amp. I look forward to your scans.

Thanks,
Todder

Killcrap should be able to help the OP

When you installed your stereo and amp what components did you install? And what original components were removed/bypassed? (pretty much looking for what was done and how it was installed) I've seen stereo shops hook the amp remote to bus wires because "a test light showed it was 12 volts" and they didn't know it was a data communication line...

since you removed DSP, i would check the k-bus wiring at the old connector, or whats left of it.

I installed a head unit, amp, and sub. I had a dsp system and removed all the dsp equipment. What you talk about may have happened.

I'd go over all the wiring in the back, odds are something got hooked to the k-bus wiring back there and is shorting the bus.

Ok guys, after tearing the back of the vehicle apart again. I was wiggling wires, and I thought I would try the turn signals. It started working, then quit again. I am not an electrician, but if it was a wire cut or something hooked to the K-bus, it wouldn't work then quit would it?? I am getting confused, any suggestions??

Todder

Sounds like possibly a wire chaffed and shorting that is grounding the k-bus that when you wiggled the harness around you moved allowing it to work, but then the chaffed spot hit the metal again.

Check all the harness routing and look for anywhere it may be rubbing against metal.

Thanks Weasel, I will look for that.

Well guys after 3 1/2 hours of poking around in the rear on my X, I have come up with some interesting information. As you guys know my fasten seat belt light is on, no turn signals in dash(turn signals work on the outside)(no hazards in dash either), no high beam in dash, no steering wheel lights and my head lights will not auto level. With that being said, I found if I latch the seat belt with my keys in my hand, then start the car the seat belt warning goes off. If I turn the turn signal on, with my keys in my hand, start the vehicle the blinker works in the dash for 10 seconds then goes off. If I turn the hazards on, with my keys in my hand, start the vehicle the hazards work for 10 seconds then goes off. With the hazards still on, turn the key off and they work in the dash again. If I turn the head lights on, with my keys in my hand, start the vehicle the head lights will auto level. Do you see a trend?? It seems as if the K-bus is working, but only before I start the vehicle. Is there a possiblility that something is wrong with my ignition?? Any ideas Weasel or Killcrap???

Todder

It is posible, but not likely as all the problems just started with the aftermarket stereo install... It sounds like something is hooked to wiring it shouldn't be and is bringing down the bus, the question is what.

Play around in this link (wiring schematics) and go over all the different connections you made and make sure none of the k-bus wires are tampered with. *note* the wiring colors are in german, so BLK is SW, Y is GE, etc.

Ok, I finally had some time to mess with with stereo. There were three wires that had something connected to them. We unhooked those wires and ran dedicated wires for power. Two of my problems immediately cured themselves: auto leveling headlights and the lights in the steering wheel. Turn signals, high beam light, seat belt lights, and driving light indicator still did not work in the dash.

Then I leave for work this morning and the lights won't auto level and the steering wheel lights did not come on. They will work correctly if I turn my lights on before I start the vehicle. With all this said, do I need to unhook the battery and reset the computer. Is there something else I can try??

Todder

Not much more I can do remotely... It may need to go to the dealer for them to trace down the whole k-bus and make sure it is in tact, and if it is find the culprit that is bringing it down.

K-bus
 

has anyone resolved this issue my wife's X has had this random issue for over a year and the stereo has been changed years before this issue and it had a aftermarket stereo in it before so no changes but periodically K-bus goes down no reverse lights or cluster indications