I’ve done it … constructed a traction control defeat device. I’m not taking all the credit for this as the concept came from Julian Edgar at Autospeed.com.au. I had to modify his design with the addition of diodes to get around the diagnostics in the CAN. But it all works. I’ll see if I can get onto the track in the next couple of weeks to put it through its paces for the definitive shakedown test.
I hate the idea the manufacturer has decided how we can drive our cars. There’s no middle ground with MB.
The AMG’s have brutal performance but you can turn off all driver aids and kill yourself. Then we have some other quite powerful sporty cars in the range like the C350CDI or C350 petrol but they wrap you in cotton wool. I live in a free democratic society not North Korea. If I want to do a track day to improve my car control skills there’s no point if the electronics are holding my hand. If you don't have an LSD then don't bother with this TC defeat as it won't help you ... in fact it will probably make the car worse. An open differential without TC is a waste of time.
There’s no option to get an LSD in anything but an AMG. Maybe it’s the marketing department trying to force you to hand over huge wads of cash for an AMG. My W204 C320CDI with its tuning box is plenty powerful enough for some sideways action since I’ve fitted a Quaife LSD but the TC is holding it back as I can't turn off ... until now.
So you need these components … I’ll provide all the detail later:
3 x small DPDT relays
1 x piece of pre punched circuit board
6 x diodes
1 x small toggle switch
1 x small warning light.
Total cost less than $40. It’s a fiddly but not difficult project needing patience and requires intercepting the wheel speed sensors at the brake control unit N30/4 … Plenty of soldering to do. There’s a big connector there with all the wires you need to get at.
The good thing about this device is the all the other aids like ABS, EBD, ESP are unaffected. ESP can already be turned off but not the TC. So if you want to do a track day you can turn off ESP and TC but you’ll still have ABS and EBD. At any time you can turn it off and the car reverts to normal cotton wool mode. You could install a keyed switch if you were prone to handing the car over to your teenage son.
Here's a photo of the N30/4 control unit where the wheel speed sensor wires connect. You can see all my intercept wires and the black box. I'll tidy up the wiring later. But it works. When you turn off the ESP you can do donuts if you want whereas you couldn't before as turning off ESP doesn't turn of TC.