DTAForum.com - a forum for the DTA ECU

Hi all.

Thinking of getting the traction control on our S80 working, manual and wiring diagram says 2 driven wheel inputs. Is there no provision for single wheel drive? (I saw there is a check box for single undriven wheel).

Could I just split a signal from a single sensor into both driven wheel inputs?

Cheers

It works with just one input, you just have to set the balance to faster wheel as 100% or something ( I has a wiring fault (car) for ages, but it still worked), or just supple the same to both inputs as you say. But what happens as you do a wheelie, the front wheel will be slowing down and will bring the traction on. I don't think with DTA you could make it work properly, perhaps the traction aggression pot on the front fork extension to reduce the aggression as the wheel comes up? or a switch to turn it off on full droop, but might be a bit abrupt.

Thanks for quick reply, for reasons I can't really expand on we don't need to worry about wheelies, so that is not an issue (I've also changed the thread title to remove that angle).

I did read the description of 'balance to faster driven wheel' in the manual and it says it "is used to allow some speed averaging across the two driven wheels". I don't quite understand what it would do with one input at zero.

Balance to undriven wheel is used to tell the ECU how much to balance the wheel speed when one is spinning and another isn't.
100% means it uses 100% of the faster wheels speed.
1% means it will use the slowest wheel. This would only be used with a very tight plate diff, as this would only allow the wheels to be at different speeds in very tight corners, so you'd want the slowest speed to be the driver.

If you only have one driven wheel, set this to 100% as Rob says, and the speed will be 100% from the faster wheel.

Thank you Alex.

So, just starting to figure out hardware for this and for ease of use am probably going to stick with the standard BMW VR abs/speed sensors. Have seen the discussions on this forum about the Siemens/GM signal converter and am going to source a couple of those to use to create the right signal for the ecu.

Regarding connecting it up, does the output of this module go straight into the relevant driven / undriven wheel input on the DTA? I saw that the module outputs a (roughly) 5v square wave, but is it ok that this is referenced from vehicle 0v not sensor 0v (although I guess ultimately they are the same thing?).

Many thanks.

I'm using them.
12v and ground are power, signal ground and signal from sensor go as expected.
You do need to connect the sensor ground of the sensor to the ECU as well to make it work.

Thanks Alex, but can't understand your instructions. I was going to connect it as the guy described in your link on one of the other thread, so;

In1/In2 are VR sensor - from what I've read polarity don't matter
15 - 12V
31 - Ground
Out - Output to ecu.

So connect 31 to signal ground, vehicle ground or both?

Thanks.

I'm on holiday, I'll have a look when i'm back on Monday. I have a lovely hand drawn sketch...

Did you find that sketch please Alex?