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    PSM + PASM tech question

    Can I have your folks' input?

    Firstly, I'm not certain, but I don't think my PSM is kicking in at all. I'm getting more wheelspin exiting wet junctions quickly than I would expect, and the other day I was a little too enthusiatic putting the power down exiting a wet roundabout, and the back slid out more than I thought it would have done considering my slow reactions at the end of a Friday commute - not a peep from the PSM.

    Q1) Does PSM allow you noticable wheel spin from stand-still before cutting power back? I seem to remember it was much keener to step in last winter.

    Now, I also have this behaviour where I turn PSM off and the handling characteristics of the car chage noticably. Straight line, constant speed, turn the PSM off and the steering and general handling sharpens up. Seems like there is interaction between the PSM and the PASM system.

    Q) Does anyone else get this? I would have thought that turning PSM on/off should have NO impact on the PASM settings. I would appriciate everyone trying this and reporting back.

    Thanks in advance

    Re: PSM + PASM tech question

    Firstly are you still on the winter tyres ?

    And in answer to your questions, i'm not much help, i haven't seen the PSM light flash on mine once in 13 months and its not through want of trying

    Re: PSM + PASM tech question

    Q1) No wheelspin from stand-still for me, though I should add that I try to be gentle to the clutch (not a big fan of traffic-light races) It really happened only once to me on wet tarmac during my pick-up tour (clutch brandnew and me not yet completely familiar with the car) and it resulted in a trampling of the rear axle (not really recommended to repeat due to high stress on all the mechanical parts)

    Q2) I'll try next weekend (I never switched off PSM completely as I have the SC, which in Sports mode provides enough fun with the less intrusive PSM settings)

    Re: PSM + PASM tech question

    Thanks guys. No Percymon, I put the summer tyres back on early last year and haven't put the winters back on this year as it has been stupidly warm.

    The wheelspin wasn't abusing the clutch, but one of the rears lost traction and started spinning the power away until I lifted enough to regain traction myself. Road was damp. Isn't traction control supposed to brake that wheel, or cut the power a bit?

    Re: PSM + PASM tech question

    You can spin the wheel a little bit before PSM kicks in. Are you seeing the PSM light blink on the dash? It does that when it's working to save your butt.

    Re: PSM + PASM tech question

    Haven't seen the PSM light for ages. Saw it last winter in the colder weather.

    Re: PSM + PASM tech question

    Hmm, the light can be frantic at times (i remember driving in the snow last MArch now ), it does allow a degree of slippage before it flashes away, but you'd have to be a sensitive driver to really notice the delay.

    I'd try disconnecting the battery for 20 minutes, to reset the ecu's and try again. Of course this will remove any fault codes stored there already

    Re: PSM + PASM tech question

    Strange, it does seem like your PSM is acting funny. For certain it should kick in as soon as it detects wheel spin (when on). Mine seems like how yours used to be. Mine is a 2005 and I also have PASM. As for affecting PASM, I've not noticed any. However, it should be the other way around. When you turn PASM on to sport mode, PSM is toned down allowing for more spin/intervening later than if PASM was in normal mode. I also have Sport Chrono and when I kick in sport mode, it tunes PASM to sport mode and turns PSM further down (PASM is upped to a sportier level than the standard PASM sport setting).

    It couldn't hurt to have your OPC check it out.

    Re: PSM + PASM tech question

    If you have the sport-chrono option, and you drive in the sport mode, the car will allow much more wheel spin, and sideways driving before psm kicks in. This was done to encourage people to not turn off the psm. That being said, I can still see my psm light almost daily when I'm feeling frisky.

    Re: PSM + PASM tech question

    I have PASM without Sports chrono and agree with some of your impressions. In general I'd describe the effect of turning PSM off in my car as a lighter steering feel, more like the 987 base I previously owned (without PASM), particular in PASM-SPORT/PSM OFF mode.

    As far as PSM/PASM interaction in your second question, the PSM variables are definitely inputs in the PASM algorithms. The PASM inputs/outputs are illustrated in the following visual:

    Re: PSM + PASM tech question

    Thanks for that input SD987



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