Crown

Hi there,

I have a strange issue on my 991 Carrera S, and I think it might be related to the Servotronic plus option.

On highways, when in a slight left turn, the steering forces me very slightly to the right for 2 seconds, and then comes back instantly on the left, like if I just had a big side wind moving the car. It's annoying enough to notice it every time it happens. It very rarely happens during right turns (actually I think it might have happened once or twice but not even sure).

I brought the car to the Porsche dealer, they drove around 100kms with the car and did not notice anything wrong. They told me the Servotronic plus would do trajectory corrections, but I can't believe what I'm experience is normal... I drive 100kms per day and I notice it every morning.

It seems to only happen when the car is "cold", during the first 20-30kms or so. It very rarely happens otherwise.

It seems to happen a bit less since the Porsche dealer added 0.3 bars of tire pressure, but it's still happening every day.

I have asked the Porsche dealer if there is anyway to turn off Servotronic plus for testing but I'm still waiting for a feedback.

Any ideas guys ?

Thx !

This is a new one on me - have you tried searching other forums? That's how I found out about the hesitation at about 2000rpm on the 9A1 engines.  The OPC were hopeless when I asked them to look into it.

Gen II Cayman S

I looked on google and did not find anything... what's the hesitation at 2000rmp ?

Very random and worse when the engine is cold or in sport mode. If you put your foot down hard, the car hesitates and then accelerates painfully slowly for a second or so.  I think it might be more of a Cayman issue but its not fun if you are trying to join a busy main road or overtake and it happens.  The trick is to just push the accelrator slightly less violently.

Touch wood, mine hasn't done it for ages.

Gen II Cayman S

Ok thx I've never noticed that... yet...

Anyone has any idea what could be wrong, or how to temporarily disable the Servotronic Plus ?

Would be interesting to know whether it can be deactivated via PIWIS. No info on that regard, sorry...

It is somewhat surprising that it occurs at a specific given scenario, so it seems to be an issue with calibration or the sensors. I find it interesting to note that it is affected by the distance travelled and the tire pressure since my first idea would´ve been the tires as well. All four tires show similar tread wear? Do you have the tire-pressure monitor on the car? Would be interesting to know whether they heat up equally fast. Those are only assumptions and no matter what the car should not give these corrections.

Please keep us updated!

Thx for the answer Ferdie !

The tires have around 3.000kms, they are quite recent and should not show noticeable tread wear. I have the TPM and the tires heat up equally fast.

So... according to the Porsche dealer, Servotronic Plus cannot be disabled.

I'm waiting for an appointment to re-calibrate it and see if it changes anything...

So... Servotronic Plus has been recalibrated, parallelism has been re-done, and the problem is still here.

It is now being escalated through the official Porsche channels.

Again, if anyone has any idea of what's going on...

BangoO:

So... Servotronic Plus has been recalibrated, parallelism has been re-done, and the problem is still here.

It is now being escalated through the official Porsche channels.

Again, if anyone has any idea of what's going on...

Has the dealer done a test-drive with a different set of wheels and tyres on your car to see if the phenomenon still shows up? 

fritz

The new steering system does corrections under certain circumstances. In your case it "corrects" without reason.

My guess is a faulty sensor somewhere or even a faulty control unit. Not everything wrong is picked up by PIWIS. I would ask the local dealer to refer the matter to the factory.

"Form follows function"

Reginos, they have referred it to the factory yesterday.

Fritz, the dealer neve managed to experience the issue themselves... But I experience it everyday ! It might be a combination of many factors...

BangoO:

Fritz, the dealer neve managed to experience the issue themselves... But I experience it everyday ! It might be a combination of many factors...

In that case, if the dealer could fit another set of wheels to your car for a couple of days it should be possible to rule the factor "tyres" in or out, depending on whether you then experienced the issue.  

fritz

Makes me worry about a major trajectory correction into head on traffic one day when the car is old and the systems are starting to fail.  Remind me again why I would want all that tech?

Since you feel it but they do not perhaps you need to take them for a drive and show them!  They may be in fact feeling the same thing but not realizing it due to how it is described and the factors involved - like it has to be a cold engine etc.

I know that when I have a rattle and I have the dealer check it they will hear nothing when driving it alone.  If I drive with them and demonstrate the noise I have their attention and can point it out live as it happens.  The fact that is mostly does it one direction is vital clue IMHO.

Still no news from the dealer, but here are 2 pics in the meantime...

1 month later, I had to call the Porsche dealer to get an update... which is that he did not receive any update from the factory...

He tells me my problem is very bizarre, but I don't give a sh*t, I want it solved !

Why don't take Fritz's advice and drive around with a different set of wheels and tires? It would rule out or in probably the likely culprit.

I'll ask the Porsche dealer if that can be done, that's good advice indeed.

Or , for the start , you can cross swap your front wheels  ( only )  and see if anything change .

Different sizes....

1987 911 Carrera 3.2 - 2012 Cayenne Diesel - 2010 Abarth 500 - 1995 BMW318ti

I still think the issue is related to the cold tires but of course this doesn't mean it should be accepted.
Has your dealer actually exchanged anything? Any part? Tires? Anything? Or just the calibration?

I have a funny issue with my PCM system on my Cayenne GTS: The built-in PCM phone doesn't "recognize" any Vodafone Germany SIM I am using in it when I turn on the PCM. I have to wait until the PCM is on and then I can insert the SIM and it works. Porsche says there is no problem (oh, really?) and if there is one (oh yeah?), Vodafone is to blame. Really? I connected my phone through BT to the PCM system but this also means that reception is inferior and it uses my phone's antenna instead of the one built-in in the car.  Reception is sometimes miserable, especially outside the city and it feels really annoying.

Still...almost 6 months passed and Porsche hasn't deemed it necessary to find a solution. My dealer exchanged the phone unit of the PCM once and got a slap on their fingers from Porsche because there is "nothing wrong" with the control unit they sent in. My dealer doesn't make a move anymore now (because they are afraid Porsche could charge/not reemburse them for every next step) and I am a frustrated customer without a working PCM phone.

Go figure...

I cannot escalate matters with the "higher hiearchy" at Porsche for this little thing but as you can see, there is something wrong with the problem solving mechanism at Porsche. Something they really need to change.

RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, Cayenne GTS (958), 991 Turbo S (ordered), BMW X3 35d (2013)

RC:

I still think the issue is related to the cold tires but of course this doesn't mean it should be accepted.
Has your dealer actually exchanged anything? Any part? Tires? Anything? Or just the calibration?

I have a funny issue with my PCM system on my Cayenne GTS: The built-in PCM phone doesn't "recognize" any Vodafone Germany SIM I am using in it when I turn on the PCM. I have to wait until the PCM is on and then I can insert the SIM and it works. Porsche says there is no problem (oh, really?) and if there is one (oh yeah?), Vodafone is to blame. Really? I connected my phone through BT to the PCM system but this also means that reception is inferior and it uses my phone's antenna instead of the one built-in in the car.  Reception is sometimes miserable, especially outside the city and it feels really annoying.

Still...almost 6 months passed and Porsche hasn't deemed it necessary to find a solution. My dealer exchanged the phone unit of the PCM once and got a slap on their fingers from Porsche because there is "nothing wrong" with the control unit they sent in. My dealer doesn't make a move anymore now (because they are afraid Porsche could charge/not reemburse them for every next step) and I am a frustrated customer without a working PCM phone.

Go figure...

I cannot escalate matters with the "higher hiearchy" at Porsche for this little thing but as you can see, there is something wrong with the problem solving mechanism at Porsche. Something they really need to change.

I read some time ago about a case of a car owner having a problem with his phone which turned out to be due his SIM card's contacts surfaces not being completely compatible with his car phone hardware. A change of SIM card (to one from a different service provider) solved the problem. It appears that "standardised" SIM cards may not all be as standard as they really need to be, if only in terms of the tolerances for the contact areas on the cards. 
I mention it because, IIRC, the card involved in that instance was also from Vodafone. Maybe Porsche knows more than it is openly saying when suggesting that "Vodafone is to blame". 

fritz

Thanks, fritz. We tried half a dozen Vodafone SIM cards (mine, mechanics and employees at the dealership) and none of them worked. Even if Vodafone is to blame (for whatever reason, still hard to believe since I use Vodafone SIM cards in many devices, incl. the PCM of my Panamera Turbo S btw.), this is not an acceptable situation for me. Six months have passed and I cannot use my build-in PCM phone, which is quite a shame. The dealer is afraid to exchange the phone module again because Porsche already gave them a slap on their fingers because of the last exchange (which hasn't improved anything). I actually could have escalated things with my dealer and Porsche but there are more important things in life. Still...this shouldn't happen and customers shouldn't ask for solutions or wait for them that long, this is not acceptable. Keep in mind that my Cayenne GTS still has a new car value of over 122k EUR, this is not a Dacia.

RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, Cayenne GTS (958), 991 Turbo S (ordered), BMW X3 35d (2013)

RC:

Thanks, fritz. We tried half a dozen Vodafone SIM cards (mine, mechanics and employees at the dealership) and none of them worked. Even if Vodafone is to blame (for whatever reason, still hard to believe since I use Vodafone SIM cards in many devices, incl. the PCM of my Panamera Turbo S btw.), this is not an acceptable situation for me. Six months have passed and I cannot use my build-in PCM phone, which is quite a shame. The dealer is afraid to exchange the phone module again because Porsche already gave them a slap on their fingers because of the last exchange (which hasn't improved anything). I actually could have escalated things with my dealer and Porsche but there are more important things in life. Still...this shouldn't happen and customers shouldn't ask for solutions or wait for them that long, this is not acceptable. Keep in mind that my Cayenne GTS still has a new car value of over 122k EUR, this is not a Dacia.

In that case, it might be more interesting to try SIM cards from service providers other than Vodafone.  

fritz

fritz:

RC:

Thanks, fritz. We tried half a dozen Vodafone SIM cards (mine, mechanics and employees at the dealership) and none of them worked. Even if Vodafone is to blame (for whatever reason, still hard to believe since I use Vodafone SIM cards in many devices, incl. the PCM of my Panamera Turbo S btw.), this is not an acceptable situation for me. Six months have passed and I cannot use my build-in PCM phone, which is quite a shame. The dealer is afraid to exchange the phone module again because Porsche already gave them a slap on their fingers because of the last exchange (which hasn't improved anything). I actually could have escalated things with my dealer and Porsche but there are more important things in life. Still...this shouldn't happen and customers shouldn't ask for solutions or wait for them that long, this is not acceptable. Keep in mind that my Cayenne GTS still has a new car value of over 122k EUR, this is not a Dacia.

In that case, it might be more interesting to try SIM cards from service providers other than Vodafone.  

They all work but why do the Vodafone SIM cards work in all other devices and the Panamera Turbo S PCM?

Sorry, Porsche has no excuse here.

RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, Cayenne GTS (958), 991 Turbo S (ordered), BMW X3 35d (2013)

RC:

fritz:

RC:

Thanks, fritz. We tried half a dozen Vodafone SIM cards (mine, mechanics and employees at the dealership) and none of them worked. Even if Vodafone is to blame (for whatever reason, still hard to believe since I use Vodafone SIM cards in many devices, incl. the PCM of my Panamera Turbo S btw.), this is not an acceptable situation for me. Six months have passed and I cannot use my build-in PCM phone, which is quite a shame. The dealer is afraid to exchange the phone module again because Porsche already gave them a slap on their fingers because of the last exchange (which hasn't improved anything). I actually could have escalated things with my dealer and Porsche but there are more important things in life. Still...this shouldn't happen and customers shouldn't ask for solutions or wait for them that long, this is not acceptable. Keep in mind that my Cayenne GTS still has a new car value of over 122k EUR, this is not a Dacia.

In that case, it might be more interesting to try SIM cards from service providers other than Vodafone.  

They all work but why do the Vodafone SIM cards work in all other devices and the Panamera Turbo S PCM?

Sorry, Porsche has no excuse here.

Sounds like Porsche and Vodafone need to talk. Maybe they haven't been able to get through?   

fritz

RC:

I still think the issue is related to the cold tires but of course this doesn't mean it should be accepted.
Has your dealer actually exchanged anything? Any part? Tires? Anything? Or just the calibration?

Just calibration, as far as I know they did not change anything.

I'm pretty sure it comes from cold tires as well... 

RC:

I still think the issue is related to the cold tires but of course this doesn't mean it should be accepted.
Has your dealer actually exchanged anything? Any part? Tires? Anything? Or just the calibration?

Interesting thought, actually. Apart from that, are your tires of a similar production date (especially the ones on each axle) and have a similar tread depth?

After 5 months, the issue has still not been fixed and I've been receiving very little support from the P dealers.

I have therefore asked the P dealer where I bought the car to take it back, now waiting for an offer...