Guys, I was discussing the ASR switch function with a friend in our 1996 C4s. We both autocross our cars, and it's frustrating that ASR defaults to "on." If you forget to disable it before a run, it kills your run. It would be so much nicer if it could default to "off." However, I don't want to yank it out altogether because there are times I might want it on, and I also want to keep ABS and cruise control functional.

So I looked up the circuit:


The switch itself is a simple momentary switch that completes a circuit to ground, thereby turning ASR off (or back on if it's already off). So the simplest workaround is to just short across the switch to have the circuit always complete. But that means the ASR switch is always defeated. Much better is to install a non-momentary rocker or toggle switch in parallel with the momentary ASR switch:



Using this, one could leave the bypass switch on to keep ASR deactivated, but the bypass could always be turned off so that the original ASR switch on the dash would become functional again.

The only concern I can think of is this: is it a problem to have the switch circuit constantly closed such that current is always running to ground? Is there anything else I'm missing here? I tried to search for previous threads on this, but didn't see any. That surprises me, so I'm wondering if I'm missing something.

 

Train yourself to start car press ASR button at every start, create a habit, or start techniech

 

Been training myself for two years. But I'm still not perfect, and I'm easily distracted (shiny things! cool!). Anyway, if it ever costs me a finishing position, I'll regret not trying to find a way to default it to "off."

 

Good luck with your project.

 

I think a 555 timer would be perfect for this. Something like what is shown here should work, but you may need a relay on the output and adjust the values for delay and pulse width.

 

That probably would cause the EBCTM will continually sense a ground on that line and may consider it a fault. Best case you get a "SERVICE ASR" light but not knowing the logic of the EBTCM could be more.

This is one of those "Need to try it" things as in the 15+ years I've been on the forum, you're the first (that I've seen) who wants to implement something like this.

 

Interesting. I hadn't considered that, but I sure can't rule it out. The timer circuit that Jim cited above would solve that. I'd have to get someone who has more snap with electronic components help me sort that out.