Menu toggle

991.1 Engine turn over issue


New member
Hello to you experts out there. I could use a little advice on an issue that my 991.1 Carrera has developed.
The issue is as follows:
Like everyone else, I havent been able to use my car due to the Covid situation, I've snuck out on several occasions just to give it a six mile leg stretch but that's about it. I start it every week to check status etc and usually keep it on trickle charge (but in this case, I forgot).
This week, I jumped in, preparing to reclaim my freedom but, no go, got the "battery low" warning message and the "start engine" message after that.
The starter engaged for a second but wouldn't turn over further. I immediately plugged in the trickle charger and left it for 24 hours.
The next time I tried the starter with a fully charged battery I got the same initial starter engagement for a split second but no further turn over. Even though the battery is testing good and showing 850 or so CCA, I tried jump starting from my wifes car. Same result. Ive tried this and also a booster spare battery but to no success.
I've spoken to Porsche Sheffield and they could only suggest to bring the car in as it's still under warranty. Obviously I can't do that and they have no transportation service at present.
My only option is to rejoin Porsche Assist for £264 and get them to pick it up but I thought it was worth asking you guys if any body has had a similar issue or may know of a resolution. I'm guessing that it is an ECU or a relay problem or perhaps linked to the immobliser but, I'm running dry on inspiration.
Apologies for the long post but hopefully someone can shed some light.
Many thanks,
Well if you're sure the battery is in top condition, then you need to check the components further down the line.
I would start with the battery terminals, earthing straps, engine earthing, connections to the starter and the voltages between each section, fuses etc.
If all this fails to reveal the problem, have the vehicle recovered to your Porsche Centre for further investigation.

Thanks for your reply Clive.
I had planned to spend today checking some of those items you listed but you’ve given me some further options to check.
Can I just ask if there are any issues regarding removing the battery without having to have the vehicle reset or whether it needs to be kept powered via a backup supply? There is a lot of dis-information regarding this, especially from Porsche Centres.

Thanks again
The vehicle is dead anyway so removal of the battery is unlikely to place you is any worse position!
But if you're worried, you have access to a second battery, so use this as a slave, although I fail to see what can be accomplished by removal of a perfectly good unit, unless you're worried about shorting it out, in which case just disconnect the earth terminal.

Hi Simon,

Unfortunately, I experienced a very similar, if not the same, issue fairly recently.

I used a mobile charger...nothing! So I called my local garage and they used a commercial-grade mobile charger (which he said would even start horse boxes so will start anything)...nothing! So I had to call out my breakdown recovery and even they couldn’t start it!! So they had to recover it to my local Porsche centre, who fixed it in no time at all.

Basically, in certain situations some kind of anti-theft mechanism kicks in and only Porsche can restart the engine. A bit of a pain but in some respects nice to know.

Good luck

Yes Clive, you’ve hit the nail on the head re a dead car, I mean, what else could possibly go wrong? (I know the answer to that, lots ??)

Once again, many thanks for your attention.
Hey Kevin,
I’ve just seen your post and your past and my present situation do sound like they parallel somewhat.
I‘m glad you posted as it maybe saves me a lot of wasted time chasing something I might never find. As you state, it does ease my mind that the issue may not be a serious fault and that a quick visit to Sheffield Porsche should save the day. I was due to go for the 35000 mile intermediate service there next week but, just got to figure a way to get it there now.

Both Clive and you have been most helpful, it is appreciated, thank you.

I had eliminated any anti-theft defect because you reported the starter partially engaging, which is unlikely to happen if this were the case.
From the symptoms you described, the problem is electrical, but it's always difficult being categoric from description of a fault. [;)]

Again, a very good point Clive, the starter does momentarily engage.
I‘ll get the overalls back on ??

Have a good day,

Hi again Kevin,
Well that sounds exactly the same then. Was it just a PIWIS plug in and reset procedure at Porsche Kevin?
I knew this was the right place to come ??

Thanks again

From what you've described, my bet would be a duff battery. Trickle charging and 6 mile trips will not have maintained a full charge. In fact, unless you have a smart charger, prolonged trickle charging can actually damage your battery. You need to invest in a smart charger. (See )

I would start there first, unless you're 100% sure it's good. Connect up your good slave battery with jump leads, whilst disconnecting the earth terminal on the one in situ, thus eliminating it from the equation. If it starts, you know you will need to replace it. If so, make sure its a Porsche approved replacement if you have Porsche Extended Warranty.


Hi Simon,

I believe so, however to be honest I didn’t ask too many questions as just glad they go my car working again as it was out of action for a few days.
That‘s a very good suggestion Clive re using the jump battery with the in-situ battery earth disconnected, I will give that a go next.

When I said trickle charge previously, I mean’t to say smart charger.

I’ve used a Sealey BT101 battery testing meter to check voltage and cranking power and as I said before, it seems to be reliable. I’ve been testing it out all week on various car, motorcycle and lawn mower batteries, some of which I’m sure are sound and some of which I know are past their best, I know, I’m a hoarder. It has come back with the results I expected each time but having said all that, I still feel the urge to try your jump suggestion.
I’ll report back on how it went, hopefully.

Best regards



Okay, It’s going, YAY ??
I did as you suggested Clive, I connected my wife’s car to the 911 and tried to jump it one final time, no joy.
I then disconnected the earth from the 911 and the power stayed on using the other cars power, tried to start it again but this time it showed all the symptoms of a flat battery ie, lights flickering and dash flashing etc but still no start.
I detached the 911 from the other car and then disconnected the 911 battery completely so the whole system was dead, my logic being that I’d come this far so I might as well start from scratch in case of a system reset procedure.
I reconnected the 911 battery and low and behold, it burst into life.
I guess that maybe a system protection had tripped when my battery was at a low ebb and needed to be reset, possibly this is all Porsche did to your 911 Kevin.

Anyway, I thank both you Clive and you Kevin for your assistance and insight, I’m on a high now and you are both heroes in my book ??

Many thanks and enjoy the bank holiday, as if we need more time off....

Congratulations, delighted you got it sorted. Persistence often overcomes resistance! [;)]

Sorry such an old thread, though I thought this might be useful as I have just been in the same predicament.
I think a dash cam flattened the battery overnight. Completely flat, the alarm was barely audible.
AA techie was running out of ideas how to start the car. Booster, jump leads, new battery still wouldn't start.
My PIWIS diagnosed immobiliser error too many attempts. Took the battery out of the key (actually replaced it with a new battery) got out of the car locked it. Held on to the lock button for quite a few seconds.
Yep on unlocking the car started as normal. Didn't have to clear any codes or reset anything with the PIWIS.
I hope this helps someone in the future.
Excellent feedback, thank you ....

Information such as this should be saved in a prominent position in `the section` ... any thoughts Admins` ?

Posts made and opinions expressed are those of the individual forum members

Use of the Forum is subject to the Terms and Conditions


The opinions expressed on this site are not necessarily those of the Club, who shall have no liability in respect of them or the accuracy of the content. The Club assumes no responsibility for any effects arising from errors or omissions.

Porsche Club Great Britain gives no warranties, guarantees or assurances and makes no representations or recommendations regarding any goods or services advertised on this site. It is the responsibility of visitors to satisfy themselves that goods and/or services supplied by any advertiser are bona fide and in no instance can the Porsche Club Great Britain be held responsible.

When responding to advertisements please ensure that you satisfy yourself of any applicable call charges on numbers not prefixed by usual "landline" STD Codes. Information can be obtained from the operator or the white pages. Before giving out ANY information regarding cars, or any other items for sale, please satisfy yourself that any potential purchaser is bona fide.

Directors of the Board of Porsche Club GB, Club Office Staff, Register Secretaries and Regional Organisers are often requested by Club members to provide information on matters connected with their cars and other matters referred to in the Club Rules. Such information, advice and assistance provided by such persons is given in good faith and is based on the personal experience and knowledge of the individual concerned.

Neither Porsche Club GB, nor any of the aforementioned, shall be under any liability in respect of any such information, advice or assistance given to members. Members are advised to consult qualified specialists for information, advice and assistance on matters connected with their cars at all times.