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    PASM suspension problem

    Regular readers of this board might know that I've been posting various topics around the handling and behaviour of my PASM equiped car.

    First up - remember when I was going on about fuel sloshing? Ignore me. Probably rear suspension fault.

    Wallowing on road undulations on bends? - That also looks like it's more to do with the same rear-suspension fault rather than an inherant PASM characteristic.

    If your car feels less than stable on twisties, you might want to consider that there is a suspension fault. Obvious symptoms are instability on performing a high-speed lane-change / elk test, susceptibility to cross-winds, vague steering feel mid-bend, general 'wallowing' on turn-in to a bend.

    These things started off small, but have recently got almost dangerous for me. I would be interested in hearing from anyone with any or all of the above symptoms.

    Car has just had rear PASM shocks replace and the electronics reset. This cured the behaviour for about 20 minutes. I am leaning towards it being either a sensor or a software issue.

    Will keep you posted!

    Re: PASM suspension problem

    Best of luck - not got any odd sensations from my PASM, bar the bone jarring ride.

    Unfortunately thats another visit to the dealer for you

    Re: PASM suspension problem

    A week since shocks replaced.
    Ride has gradually got softer.
    It seems like PASM doesn't want to control anything.
    Behaving like cuising barge again.

    Re: PASM suspension problem

    Well not to add more possiblities to chase, but the new EXCELLENCE in the US has a mention of the PASM lateral "lurch" to be caused by too soft motor mount?! The speculative fix from one tuner was to use the X71 mounts. YMMV.

    Re: PASM suspension problem

    I'm having similar problems with PASM equipped Cayman S. Suspension seems to be very firm even in normal mode, but car is very susceptible to cross-winds and doesn't feel 'planted' mid corner, and has occasionally lurched sideways on the motorway. I'm taking it back to my OPC tomorrow to see what they have to say.

    Re: PASM suspension problem

    Good deal that you follow up on it WTSnet. Keep at it until it's fixed.

    Re: PASM suspension problem

    I currently ordering an 07 987 with PASM. Should I change my order? I like the way the 06 drove on an extended test drive.

    Re: PASM suspension problem

    I would worry about it. If anything is wrong with PASM, they should have it cleand up by the MY07

    Re: PASM suspension problem

    After break-in and got the over-inflated tyre issue sorted out, I am actually beginning to like the PASM set-up...

    Re: PASM suspension problem

    I think the PASM system is very good, however with complexity comes a greater risk of fault. And I'm sure that if you did have a problem, Porsche would want to fix it rather than try to ignore you.

    PASM suspension problem - Update

    Took car to Towcester OPC this Saturday.
    Tech test drove, and agreed that handling was rubbish.
    Examined components in workshop, and found nothing obviously faulty. Thereupon, refused to spend any more time on it, as they couldn't get their money back from Porsche for any test driving/investigation. Strong perceived implication that as there was nothing physically faulty, I must be imagining it. Grrr! Pushed me back in the direction of Exeter OPC.

    However, driving this evening, the car has been performing like a ballerina once more. Exellent body control. Will call OPC tomorrow to find out the extent of their fiddlings, but the clock has changed (The time is now wrong!) and the 'Service Now!' warning has gone (It was counting down, even though I had it serviced at around 15k). So they must have done some degree of system reset on Saturday.

    Further observations: When 'fixed', the car a) Has good body control. b) Doesn't squat/dive on accelleration/braking.

    Looks like I'm going to have to bite the bullet, lose a weeks pay - Pounds1200! - and spend a week with OPC Exeter sorting this out. Annoyed that OPC Towcester were not keen to help, as they are only 45 mins from work, and we could have sorted it out over the course of a few days.

    Really wish Porsche OPCs would get it into their head that the sort of folks that buy their cars just don't have the time to bugger about. Service depts opening only Saturday morning is pitiful. I'd rather they were working all weekend and had one or two days off during the week! Or at least paid attention to customer's symptoms, kept a dialogue open with them as the car was being worked on, and focusd on getting things fixed first time, saving both workshop and customer time in the long run.

    Re: PASM suspension problem - Update

    Well its fixed (sort of!) for now (fingers crossed)

    But yes, its disappointing that having agreed the symptoms were there and were not typical for the car then they should have followed it through. The trouble is what do they change first, if there is nothing in the diagnostics ?

    Either way it wouldn;t have been too much trouble for them to email Porsche Germany Technical for advice.

    I still think you should write to cstomer Services at Reading HQ and copy to your local OPCs, detailing each visit, symptoms and reaction at the OPCs. Its a sad fact that with these types of issues you have to push to get any progress.

    Re: PASM suspension problem - Update

    What's the latest news on your Boxster's PASM fault? I'm still struggling with my Cayman and interestingly Exeter is the supplying dealer...

    Did the system reset fix the problem for good?

    Re: PASM suspension problem - Update

    No, as per usual, it deteriorated again. Actually, though, this time sharp handling returned spontaneously (at the end of a 160 mile drive), but soon worsened again. It's really difficult to say, but it felt like the active control was cutting out, leaving the shocks 'stuck' in whatever position they were last in. There was a time when, like you, I was stuck in a bone-shaking ride.

    I haven't had time to persue, though I have the week off, and trying to get the car sorted was on my list of things to do. I was trying to get a decent comparison test to firm up my opinions.

    I have two thoughts.
    a) PASM control just doesn't like my driving style. Possible, but I'm not convinced.
    b) There's a dodgy sensor/wiring/control unit.

    Are Exeter refusing to investigate yours at all?

    Re: PASM suspension problem - Update

    You're not going to like my answer, but I think your problem is A.

    I came off a 987 base that I put 20K miles on so I was well acquainted with how well a Box should handle.

    I switched to an 06 S with PASM and during break-in I was like WTF? You're quite right, the handling felt positively dangerous...on 19s. OK maybe by normal standards, but definitely not up to snuff. I didn't notice dive on acceleration or braking, but the car always felt on edge well before the "known" limits.

    After break-in and the corresponding change in driving style...all good. However I didn't notice the change until about 1,000 miles ago (about 4k now), obviously only a portion of that was driven.."aggressively".

    It seems a couple of things that PASM doesn't like, is extreme maneuvering at A), low-engine revs (4500 and below) and B) lift-off when maneuvering (a general no-no anyway, but when you're worried about engine revs, during break-in for example, there's a conflict).

    So practical advice I'd give you is to stop babying your car. When maneuvering at speed, maintain the 5000-6500 range more. Even more specific, don't build your revs gradually with lighter acceleration. Dip into that throttle and build revs quickly. Lighter throttle/rev buildup combined with extreme maneuvering seems to confuse the car as to your intent.

    If the tester felt good with PASM out of the box, consider the kind of driving people do on testers

    YMMV but the above worked for me.

    Re: PASM suspension problem - Update

    SD987, many thanks for your input. Little insulting, but thanks for contributing.

    My driving style is mixed. 80% of the time in my weekly drive, I'm commuting at 80(ish)mph steady speed. Obviously I'm in 6th.

    The rest of the time I'm in town or on twisty country roads, where I am anything but gentle.

    If I'm hammering round some country curves in 3rd at 70mph, and the car feels like a boat - you know you could probably do 80, but you just don't trust the car - I'd say that was a problem in PASM control.

    Likewise, you're cruising at 60, admittedly in 5th/6th. Suddenly you need to do avoid something. I expect the car to respond (reasonably) swiftly and precisely, and not feel as though I'm about to lose it due to hopeless body control. This is a car that can slalom better than an Enzo, allegedly!

    I hear what you are saying about PASM preferring certain conditions, but this feels like it's asleep most of the time. 2 techs have agreed with me so far.

    Re: PASM suspension problem - Update

    Quote:
    SD987 said:
    Lighter throttle/rev buildup combined with extreme maneuvering seems to confuse the car as to your intent.



    Then, the PASM is at fault. A normal suspension setup doesn't get unsettled by light throttle hard steering inputs, infact, it is the key to smooth driving.

    PASM should not ever get 'caught' out. if so, its either a crap system, or at fault.

    JZ

    Re: PASM suspension problem - Update

    No matter what your driving style the PASM should never get stuck in bone shaking sport mode if you have normal selected on the dash.

    I've done sweeping A roads at crazy speeds (WELL over 100mph during advanced driving tuition)in normal mode and the car never felt anything but settled and stable - in fact i'd go as far as to say i never noticed any transition in damper settings within 'normal' mode during the period.

    I still don't use sport mode though - its so damn hard its uncomfortable and compromises grip on less than mirror smooth surfaces.


    Whilst its taking up both your time and effort, you really do need to try another example to compare, even do the same route in your own car afterwards.

    Re: PASM suspension problem - Update

    Quote:
    percymon said:Whilst its taking up both your time and effort, you really do need to try another example to compare, even do the same route in your own car afterwards.


    I know I know! I was angling to take something out yesterday, but there's a distinct shortage of cars taxed to test at the moment - generally, not just Porsche. There should be a 3.4 Boxster and Cayman S available on 1st though. I did have a 2.7 tip with PASM a while ago, which was much better, though found it difficult to get to grips with the tip. It likes shifting into 5th when you're not looking...

    Re: PASM suspension problem - Update

    Just an update to keep the thread current.

    Took the car to OPC Bournemouth (Chapelgate) this morning after a particularly disheartening commute back on Friday night. Car obviously sensed that I was angry with it, and frustratingly was pretty well behaved, so couldn't demonstrate problem properly. Have to say though, that in contrast to Towcester and Exeter, the level of customer service I got today was so much better, right from reception, to service manager, to tech, to sales staff. Genuine interest in the problem, taking time to discuss and test drive the car with me, without ever making me feel like I was wasting their time, or looking at me just like I was a walking cash register. And I wasn't kept waiting!

    Big pat on the back for all staff at OPC Bournemouth.

    I'm going to have to spend more time with them when I can, which isn't going to be for a couple of months.
    Possibilities are:
    - Sticking PASM valves
    - intermittent bad signal from one or more sensors
    - something to do with how PASM is interpreting my driving style
    - something to do with PASM control deterioration after a long drive.

    Unfortunately they didn't have a comparable Boxster/Cayman for me to take out today for comparison.

    Will post continued findings. However, something that may seem to temporarily confuse (my) PASM is hard acceleration round a gentle left bend (IE when coming off a roundabout and then lightly touching the brakes, or just coasting (due to slow traffic ahead) rather than continuing to accelerate hard when you up-shift into 3rd.

    Will keep posting observations.

    Re: PASM suspension problem - Update

    Quote:
    wtsnet said:
    Big pat on the back for all staff at OPC Bournemouth.




    Glad you found them as first class as I have. Even when I first went there thinking about my first Boxster I was treated superbly - and I drove there in a Ford Focus Diesel.

    Re: PASM suspension problem - Update

    I've just doen 1350 miles around Scotland this week using anything bar motorway where possible, inclusing several mountain passes and coastal trails.

    Conclsuion - still think PASM is way too hard in sport mode for anything bar super smooth tarmac. Normal mode much better on the bumpy stuff, allowing far greater grip. It was interesting that every time i switched to sport the Boxster drivers behind commented how unstable the rear axle seemed when pushin on (no PSM interaction).

    I think the best you can do is drop the car by when you have the problem and leave it running while you grab a techie - not exactly convenient !

    Re: PASM suspension problem - Update

    My 997 C4S developed PASM failure when it had covered only 185km. 'PASM failure' came up on the instrument cluster and the suspension became rock hard. Shutting the car off and restarting it right away would cure the problem until it happened again a few kms later. This convinced me that it was an eletronic/software issue. Occasionally the warning message would not come up, but the suspension would still become rock hard.

    The local Porsche Centre took the car in, and they promptly replaced the PASM control unit and all was well again. If anything the car now drives better than before, so I guess my car had a dud PASM control unit from day one.

    I still find PASM 'Normal' too soft even given our lousy roads in HK, and PASM 'Sport' is simply unusable. With hindsight I should have gone for the -20mm Sport Chassis with LSD but there was no demo car availble with this option. Live and learn.....

    Perhaps in near future when Bilstein have a PSS9 kit for PASM-equipped C4/C4S, I will take the plunge. At present they only have a PSS9 kit for PASM-eqipped C2/C2S. All my other cars have PSS9 and it is a fantastic coilover set-up.

    Re: PASM suspension problem - PSM interaction

    TVman and all, I might have a temporary fix / diagnosis tool to try....

    As you know, I took the car to OPC Bournemouth last week. One of the things I noticed on the test drive with the tech was he turned the PSM on and off. I wondered at the time 'why the hell is he fiddling with the PSM - it's a PASM problem!'. To my mind, it's like turning the ABS on and off!

    Since last weekemd, when the car was reasonably well-controlled, the PASM seems have gone to sleep again. On the drive home last night, I idly thought 'I wonder what happens if I turn the PSM off'....

    And what do you know, it seems to wake up the PASM control. I was stunned.

    The ride quality improved no end. I really wonder if the valves in the shocks were left to drift around by themselves, and were moving around in sympathy with the movements of the suspension.

    Steering turn-in is much more immediate and has more weight.
    Feedback through the steering wheel is much better.
    High speed stability is much much better.
    It feels like high-speed rolling resistance is lower. (I guess due to the smoother ride) and mpg seems a little better.

    And here's the clincher - you can feel the PASM settings change with driving style. If you're cruising in a straight line, the steering becomes 'comfortable' (difficult to describe). However if you try some small left-right-left inputs, you can feel the steering gradually sharpening up back to go-cart response over a few seconds.

    So.... What the hell is going on then??

    I'm not 100% sure, but I suspect that even with PSM turned off, the PASM control starts to go to sleep after 100 miles or so. Haven't tested if it gets spooked by a sudden high rev to low rev 'lift off' like I mentionned before.

    But, TVman, I'd be very interested if turning the PSM off on yours fixes anything. Have you tried before?

    Cheers!

    Re: PASM suspension problem - PSM interaction

    The benefit is of course that PSM isn't actually turned off - it's still there for extreme situations. I guess these things are all interlinked. Be worth feeding that back to Bournemouth though - might aid them in tracking down the problem.

    Re: PASM suspension problem - PSM interaction

    Quote:
    wtsnet said:
    TVman and all, I might have a temporary fix / diagnosis tool to try....

    As you know, I took the car to OPC Bournemouth last week. One of the things I noticed on the test drive with the tech was he turned the PSM on and off. I wondered at the time 'why the hell is he fiddling with the PSM - it's a PASM problem!'. To my mind, it's like turning the ABS on and off!

    Since last weekemd, when the car was reasonably well-controlled, the PASM seems have gone to sleep again. On the drive home last night, I idly thought 'I wonder what happens if I turn the PSM off'....

    And what do you know, it seems to wake up the PASM control. I was stunned.

    The ride quality improved no end. I really wonder if the valves in the shocks were left to drift around by themselves, and were moving around in sympathy with the movements of the suspension.

    Steering turn-in is much more immediate and has more weight.
    Feedback through the steering wheel is much better.
    High speed stability is much much better.
    It feels like high-speed rolling resistance is lower. (I guess due to the smoother ride) and mpg seems a little better.

    And here's the clincher - you can feel the PASM settings change with driving style. If you're cruising in a straight line, the steering becomes 'comfortable' (difficult to describe). However if you try some small left-right-left inputs, you can feel the steering gradually sharpening up back to go-cart response over a few seconds.

    So.... What the hell is going on then??

    I'm not 100% sure, but I suspect that even with PSM turned off, the PASM control starts to go to sleep after 100 miles or so. Haven't tested if it gets spooked by a sudden high rev to low rev 'lift off' like I mentionned before.

    But, TVman, I'd be very interested if turning the PSM off on yours fixes anything. Have you tried before?

    Cheers!



    Hi Wtsnet,

    Interesting thought, and no, I've never tried turning off the PSM to see if it affects the PASM. I will now. But, anyway, the car is off to Reading on Wednesday - hopefully there will be some sort of resolution then. If not, I think I might sell it.

    Re: PASM suspension problem

    Just to bump this thread a bit, and to post cross-ref link to CaymanClub.net thread of related issue:
    http://www.caymanclub.net/showthread.php?p=80113#post80113

    Hope you're all having a great weekend with your p-cars.
    Watch out on those frosty roads in the UK.

    Re: PASM suspension problem

    Well, I finally managed to get some time to take the car to the OPC and leave it so they could drive it for a bit to see what they thought. (This is OPC Bournemouth by the way).

    They agree (after driving it around for half a tank) that there's something not quite right, and after referring to Porsche Technical they are going to replace the PASM control unit. This is the result I wanted, and it will be very interesting to see if it fixes it!

    OPC have been very good. I guess it's difficult for them when a customer brings a car to them with a vague fault. The car needs to be driven for an extended period so the fault can reveal itself, but the dealer has no idea if the cost of the time spent doing so can be recovered under a warrantee claim.

    Will be a week before the part is in, and I'm not sure when I'll be able to get the car in to fix, but I'll keep you folks posted.

    Re: PASM suspension problem

    Did the new PASM unit solve the problem?

    Re: PASM suspension problem

    I got the PASM control unit swapped last Wednesday, and picked up the car on Saturday.

    It feels a lot better, but I want to give it a more extensive test before posting conclusions. Watch this space...

     
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