dwebb944t

Hmmm... Same buttons I have been using! Thanks guys for helping me understand my car rocks and my driving skills are superior! I don't need no stinken traction control!

pfbz

They are very different...

Electronic traction control (ETC) is pretty basic. It is designed to emulate a limited slip differential and provide balanced torque between the two rear wheels, as well as prevent both rear wheels completely spinning by reducing power. ETC operates on rear wheels only, which is probably why stability management (PSM) came standard on the all wheel drive models...

An oversimplified description of how electronic traction control works:
- Monitor rear wheel ABS sensor to detect single spinning wheel.
- - If single wheel is spinning, apply braking force to spinning wheel.
- - - This diverts torque to non-spinning wheel, acting like an electronic limited slip.
- Monitor rear wheel ABS sensors to detect BOTH wheels spinning
- - Electronically reduce power given to rear axle
- - - This hopefully reduces both wheels spinning. If you are on a super slick surface and uphill, it can result in simply no forward motion...

Stability management, on the other hand, does the above plus can correct for severe over or understeer, helping to prevent or recover from spins. It uses a yaw sensor (rotational force), the ABS wheel speed sensors, ECU sensor, brake sensor etc. and can apply brake pressure any wheel, even the front wheels, individually. For example, if it thinks you are entering into a severe oversteer spin, it might apply brake force to the outer front wheel as well as gently reduce power.

No matter how skilled you are as a driver, you aren't going to be able to brake a single wheel using the brake pedal.... Skill might help prevent you from getting into a snap oversteer situation, but PSM will exceed any drivers skill in recovering from it once it is happening. The trick is for the computers to allow a bit of slide and yaw before interceding so it still drives like a sports car, and from all reports, PSM seems to rarely 'intrude' on the driver experience.

cringely

for those of us who don't have PSM, can this be retrofit? And, if so, how much of a hassle (time, $$, etc.)? Or is the idea of retrofitting PSM just wishful thinking?

Ray S

This IMHO

Imo000

Thanks for the explanation. So this is then what they call a "Makes heros out of zeros" option.

Steve's MLC

All the 2004 40th AE's have PSM, and there is a button on the dash, which I dare not touch.

dwebb944t

Chicken! I hope you are kidding, if not you should at the very least go to a local auto cross event and learn to drive car with your feet and hands sans the nanny!

gwhaley

Hi, all. Just wondering if anyone knows if ^^^ is possible? I've done some searching here as well as other sites, with no luck. Not sure if I really need it, but it'd be nice to know whether it's feasible or not. Thanks, Greg.

Recently acquired 2003 996 C2 coupe. 6spd. Red)))

pfbz

Possible, perhaps, but just barely.

Maybe if you had a salvage car with PCM you maybe could harvest all the parts from it, but that would still leave you with the extremely difficult job of trying to get all the software loaded and playing nicely with your existing systems. that would additionally require lots of knowledge as well as access to Porsche programming tools and correct software.

Not even remotely practical.

sandersd

+1 Once you drive your car at an autocross you will realize the PSM can interject itself into situations where it's not wanted or welcome.

MiamiC70

I have to say is all PCM does is ruin a perfect rear end slide. You are thinking "I got it, I got, it" and all of a sudden boom the car jerks like you just suffered from a spasm mid slide.

Turn it off have some fun playing in he rain

jaeastri

^ Agreed. One of the things i love the most about my 03 C2 is that the only electronic nanny it has is ABS

wwest

PSM is for those thousands of miles you drive with your mind not fully attentive!

GuardsTurbo

PSM is just a more sophisticated traction control, nothing more.

SproutSprawl LLC

I'm looking to add the PSM button option to a 996...is $1,250 how much Porsche was charging to include this "option" on these vehicles? Local shops are saying $10k to add