dcaranci

Hi,
I did a search and it sounds like a couple of people out there have had a similar problem as myself with the steering wheel heater, press the button, it stays on for 10-15secs then shuts off, no steering heat produced.

Dealer wants $200+ to "diagnose" it as it's not under warranty. Likely swapping out the wheel might solve the problem, however before I go out an buy one, I want to make sure that's the problem first.

I'm pretty handy with a meter and screwdriver, and from what I can tell after removing the airbag, the element seems to be fine. But I don't know where the relay, thermostat, etc... is.

Does anyone out there have a wiring or circuit diagram for the steering wheel heater? If so, I would REALLY appreciate a copy of it.

Also... it looks like I'm looking for a good SPORT steering wheel with WORKING heater, no airbag req'd (mine is fine).

Thanks...
D

dcaranci

Nobody has this? If anyone can offer any help, I'd greatly appreciate it.... PLEASE?

dcaranci

Ok, maybe someone who knows the BMW electronics can help me out with this.
I did some more tinkering today, took the wheel apart and found the 4 wires that run from the bus module (I think it's called that) to the perimeter of the wheel. 2 are very tiny wires which I assume are the thermo sensor and 2 are heavier which I'm sure are the element wires.

So, I after disconnecting everything I applied an external 12V to the heating element wires and presto the wheel gets warm. GREAT so the element is fine!

Then I checked the resistance across the thermo sensor, it's not a thermostat because it seems to vary with temperature of the wheel as opposed to simply an on/off switch. So it appears to actually measure the temperature of the wheel and send that info back to the bus module.

So... what I have prooven is that I believe the wheel itself is is perfectly fine. The issue appears to be either a software glitch somewhere OR a problem with the little bus module inside the steering wheel.

Questions:
1. If I can find another of these modules somewhere, will simply exchanging it with mine cause any alarms/warnings that I would need the dealer to reset (at another $65)?

2. Anyone know where I would be able to find this module and what it's actually called?

3. Anyone know if this module is the same one used in ALL steering wheels, regardles of type (standard, sport, M, heater, etc...)?

4. Based on the info above, does anyone have any other thoughts as to the problem? Based on my experience and knowledge I doubt a sotware issue would cause only a single issue like this, and I also doubt an problem with the bus module since this same module interfaces with the airbag and steering wheel controls which all work fine. I'm baffled, but what else could it be???

Thanks to everyone for any help...
D

porsche911targa

Hi, sorry I don't have an answer for you, but I'm very impressed by your DYI ability. Although I have noticed that this forum is a great way to get information, I deduce (based on the few answers I receive, whenever I have a technical question) that most people here are more into Mods and are quite knowledgeable in that arena. It would be nice if we had more professional BMW techs as members, but then again, if they were to dish out all the info they know, it might just put them out of business. Good luck to you.

Ghostteck

Hey "D" i have the same probably my steering wheels heater doesn't work any more if you find a way to fix it that doesn't cost an arm and a leg like it does from the dealers let me know!

Speed_Force_E60

Well if you dont figure it out soon, my offer still stands... in fact I may add more $$$ on top of what I offered just because i want it

andy535xi

might help
http://www.realoem.com/

bruce_miranda

I think the front heated seats and the steering wheel share the heating module (this is why you can't order the wheel without the seats). Check that too. But the way I believe this must work is that the heating ECU sends a signal to apply power or not to the heating element and since you say the element is fine it must be the module that is at fault or the software driving the module.

schulrog

the steering wheel and seats do not share the same ECU!

Anyway, if you replace the ECU for the heated steering wheel you should be fine without any errors. Very good on the temp sensor Actually, you have 2 wires from the steering wheel going to the coil spring which is where it gets it's power from. One is a 12V and the other is the temp sensor.

If you check out the wiring diagram...

on the steering wheel control module side: 1,2,3,4,5,6 -> is for multifunction buttons etc.
5,3-> is for the heated steering wheel. KL30 is the 12V and KL31 is the temperature sensor.

In the other pic you see the steering wheel module with part#: 61316953322 -> with heater, without SMG; 61316953321 -> with heater, with SMG

hope this helped. if you need any other info or have thoughts hit me up.

cwmenne

My '04 545i just started this exact same thing. Wondering if you've found a fix for it yet. I did notice,(before it failed), that the top of the steering wheel would sometimes get so hot that you couldn't touch it. I wonder if this is an indication that the temp sensor was going bad. If the sensor goes bad, it may still read a change, but be out of range of what the computer will allow it to run. By the way, did you see a mV output (thermocouple) or a resitive output (RTD or thermistor)? If we know what type of output it is, we can measure it for accuracy.

I'm hoping you've figured it out, so I can get mine fixed too.

Thanks!
Chad