Instrument Cluster/ K-Bus Urgent!!!! PLEASE

[yony5]

Hi , im new here but Iv had my z4 3.0i for 5 years now. Got it as a gift from my parents for graduating highschool, & i just recently graduated college so Ive have not been able to make enough money to send my car to get checked.

Ok so its been a struggle because about a year ago water came in through the back of the car and ever since ive had major electrical issues.
To the point that the car cause i was still in college, i had to leave it parked for about a year only because it stopped starting up.
I ended up walking n biking the 7 miles. Ive taken apart the car about 4 times checking cables for corrosion or pinches. I found none. Ive looked around and it seems some module is damaged sending a signal to the k bus to shut down everything.
Symptops
-interior lights dimming
-radio sporadically turns off
-heated seats dont work
-car eventually stopped turning on , i played around with the fuses taking one out n putting it back it and car would start sometimes

i Found that the buses send the signals to the Instrument Cluster , so i figured that if i pull out one pin at a time the system would go back to normal if the pin i took out had the bad module,and then i could trace that cable back. Everything was going well until i had to go pick up my siblings , I left a cable out and i dont remember where it goes.

Its the 26 pin connector behind the instrument cluster. Please if anyone can just post some pics of that 26 pin connector or a pin-out diagram
pics(preferred), I would be forever grateful. I just wanna put it back together, and send it off to a shop to get it checked.

 

[GuidoK]

What are the last 7 digits of your vin?

 

[Chris_D]

Come on OP! it's Guido to the rescue here!!
Get ur vin number posted. jeez.
:roll:

 

[yony5]

OMG thank God , i thought I was alone with this problem, Here is my vin 4USBU33597LW72485

 

[GuidoK]

You are alone with this problem. I always get my car back together :rofl:
I need your vin to see what exact date your car was made and what exact engine you have to look up the data. (all wiring data is in bmw WDS but that has a bit of a learing curve to use) so I'll get the data for you.

Ah, US only 218HP 3.0i n52 engine; 2007-06-13 prod date, alpine white.

 

[yony5]

you my friend is what we call a BOSS, coming in clutch

 

[GuidoK]

schematic of the connector (pin numbering):

Pin function assingment (this is what all the pins/wires do if you want to do fault tracing):

Pin assignments at plug connector X11175
Pin Type Description / Signal type Connection /Measuring notes
1 M Ground Ground connector
2 E Signal Parking brake Connector Parking brake
3 E Terminal R Fuse F12
4 Not used
5 E Terminal 15 Fuse F23
6 E Signal Processed wheel speed, rear left Connector Processed wheel speed, rear left
7 E Terminal 30 Fuse F24
8 E Signal Warning lamp Dynamic stability control (DSC)
9 E Signal, terminal 50 Electronic vehicle immobilizer (EWS)
10 E Signal, steering column switch Direction indicator/high beam headlight switch
11 M Signal, fuel tank sensor ground (left) Electric fuel pump
12 M Signal, fuel tank sensor ground (right) Electric fuel pump
13 M Ground, outside temperature Outside temperature sensor
14 E/A K-bus signal K-bus connector
15 Not used
16 E/A CAN bus low Connector CAN bus low
17 E/A CAN bus high Connector CAN bus high
18 E Signal, brake wear sensor Brake pad wear sensor, front left
19 E Signal, coolant level too low Coolant level switch
20 Not used
21 E/A Diagnosis signal TXD Diagnostic connector
22 E Reverse, manual transmission, shift to + Connector Reversing lights
23 E Signal, washer fluid level Wash water level switch
24 E Signal, fuel tank sensor (left) Electric fuel pump
25 E Signal, fuel tank sensor (right) Fuel level sensor
26 E Signal, outside temperature Outside temperature sensor

Connector schematic:

If the above pic is too hazy, I've uploaded the schematic also as pdf:
https://audio.home.xs4all.nl/zooi/z4/div/WDS%20Wiring%20Diagram%20System%202006_09.pdf


In the above pic you see around the central gray area (schematic view of the connector) all lines going to it. those are wires. The number displays the pin number (placed corresponding the first pic in this post), and there is also a colour code, for instance BR/SW/WS (on pin 11 for example).
That means that that is a Brown/Black/White wire. So probably a white wire with a brown stripe and a black stripe (or a brown wire with a black stripe and a white stripe... you get the idea)

Full Colour schematic:
Wire Color
Color BL Blue
Color BR Brown
Color GE Yellow
Color GN Green
Color GR Gray
Color OR Orange
Color RS Pink
Color RT Red
Color SW Black
Color VI Violet
Color WS White
Color TR Transparent

I dont know if all the wires are loose, but its just a giant puzzle. See which wires you have, look them up where the colours are in the schematic and see which pin number they have and then locate that pin number in the connector.

You can root around in bmw WDS (bmw wire system) here:
http://www.bmw-planet.net/diagrams/release/en/
Everything is in there, but you have to get the hang of it how the interface works (and you probably have to install or update java)

edit: changed pdf link to better server

 

[yony5]

WOW!, thanx a million. I just have one other question if your still there. By Any chance do you know where i can find the K-BUS on this car. Ive seen online with 3-series owners that delt with k-bus issues, they locate the kbus that has about 9-12 cables color code white/red/yellow and they can trouble shoot through there.

The that connector hub is what ive been looking for but its obviously different on the z4 than the 3-series. BTW thank you soo much for the info seriously

 

[GuidoK]

Pin 14 is K bus on the instrument connector
But I dont know how to diagnose that.

I know you can get little interfaces for the Ibus, but I dont know how I bus and K bus are related.
its often referred as I/K bus.
the I bus interfaces (from resler) hook up most easily to the cd changer connector (CD changer has 2 connectors; an audio connector and an Ibus connector)

 

[yony5]

ahh alright , you are the man!!!!!

 

[mac27040]

use this as it has all the wiring diagrams

http://www.bmw-planet.net/diagrams/release/en/e85/index.htm

need to run in internet explorer and get you java settings right.

 

[GuidoK]

^thats the link I also gave in this topic, but for me it runs fine in firefox. The java is irritating though. (I installed java to get it to work)

 

[buzyg]

use this as it has all the wiring diagrams

http://www.bmw-planet.net/diagrams/release/en/e85/index.htm

need to run in internet explorer and get you java settings right.

Nice Added to favourites.

 

[ph001]

Strange post revival bot??? Anyway, I know where the op’s problem will be for anyone still around two years later that’s interested! It’s the airbag control ecu that sits underneath the console between the seats that will be wet / coroded.