RPM/Tachometer Signal Wire?? SOLVED
 

Anyone know where I can find the rpm signal on a 2006 with the N62 engine? I’m trying to set up a shift light kit and I need to tap into that signal somewhere, trouble is...I can’t find.

l believe there is a turbine in speed sensor on the transmission. Also the data is available on the buss I don't know how it's accessed but a lot of people will connect their head units to it.

I would think that either the crank or cam sensor could be used and both should be available in the E-box to make a nice job of it. Read the instructions with your kit and get a wiring diagram.

Crank and cam output very odd compared to rpm. Crank probably direct multiple but cam very weird.

Not as easy to do on Canbussed' based vehicles. You're likely going to need something that can plug into the OBD and will likely be run off software rather than based on a quote tachometer signal which usually follows with distributor ignition systems.

Yahhhh, definitely (a tad) insulted that you would suggest I would skip right past something so obvious and comparatively simple as reading the instructions and a wiring diagram, and come straight to xoutpost. Actually, there was no instructions included specifically on wiring for the tach signal (personally, I haven’t mastered the art of reading instructions which do not themselves exist!)

Anyway, I first acquired a pin out for each dash cluster connector (from a BMW specialist mechanic) and found that the “TD” wire of the CAN bus was not suitable for the device I’m using, which requires a sinusoidal wave signal (the CAN Bus signal then must not be sinusoidal or otherwise is not suitable for my application in some way). So, after the wiring diagram failed to produce a suitable tap-in point, and the manufacturer couldn’t tell me which signal it was for my specific vehicle (no surprise there), I went back to the internet with a suspicion that the OBD II port (as was suggested above) would be my route (if TorquePro or OBD Fusion could get RPM data from my engine, so should I). A couple of days later I managed to find a BMW related OBD port pin out that showed pin #9 on the OBD connector was a tachometer signal. (Furthermore, I’d read, on another forum, a thread where someone had used an oscilloscope to confirm this very wire’s signal was sinusoidal) I tapped into that wire and low and behold my shift light works flawlessly. And this after even BMW mechanics told me I wouldn’t be able to do it on a “CAN bussed” vehicle, which just goes to show you, where there’s a will there’s a way.

Here’s the Pin out that I used (apparently, applicable to all BMW models after 2000:

1 - +12V (ignition, in run or start)
4 - Chassis Ground
5 - Signal Ground
6 - CAN high J-2284
7 - ISO 9141-2 K-Line (engine, ISO-9141 and ISO 14230, automatic transmission diagnostic)
8 - ISO 9141-2 K-Line (IKE/KOMBI, ABS, ABS/ASR, ABS/ABD, ESP, DSC, Airbag and other electronic equipment)
9 - TD/RPM
14 - CAN Lo J-2284
15 - ISO 9141-2 L-Line (of ISO 9141- and ISO 14230-4)
16 - +12V (battery power)

nice find. I was looking for the same thing when I installed a Pioneer head unit into our X5 and could not find the answer.

Great follow up.

thanks for your followup. this information and data can really help the community.

Of course! I’ve leaned so much on this forum in the past for help myself, it’s a pleasure to be able to add a tiny bit to it myself.