Totally Dead 992 Turbo! Any thoughts? - Page 4 - 911/Carrera GT - PistonHeads UK

Hi All - after loads of googling & YouTubing, I’m coming to you. My MY24 992 Turbo is dead as a Dodo! I’ve been caught up in the whole centre lock thing, so managed to get Porsche Reading to send me a trickle charger. Clearly I’ve balls’d something up - had it plugged into the 12V port and rather than pushing in power, it’s clearly been going the other way. Managed to unlock the car with its last gasp of electricity and now it’s totally deal. Absolutely nothing. Can’t even pop the trunk to get to the battery. I’ve found the emergency hatch in the passenger footwell - Hooked the jump-leads up to a Macan, but to no avail, all still lights out. A company are actually coming over tomorrow to put the car on a trailer to have the centre locks fixed, however i can’t release the handbreak! Any help or thoughts appreciated. Thanks guys!

I would trickle charge over night - and hope. But connect to battery not the cigarette lighter. Make sure the mode on the CTEK charger is set correctly too if you have more than one option (AGM in your car I think).

Discombobulate said: I would trickle charge over night - and hope. But connect to battery not the cigarette lighter. Make sure the mode on the CTEK charger is set correctly too if you have more than one option (AGM in your car I think). I can’t open the bonnet to get to the battery!

Battery is lithium. It has a contactor in it, you can’t just charge it if it’s dead. It’s now protecting itself.

My 992 went dead. lithium battery CTEK did nothing Porsche came out and jumped with a pack which woke up the system. Any jumper pack will do, doesn't have to be lithium Then drove the car for a few miles Then trickle charged Apparently nothing will work until the car receives a jump charge Im sure someone will explain more correctly than me, but that was the gist!!

acwh said: I have had this, completely dead, had to use physical key to get in. If you follow the instructions to the letter using the passenger footwell access to get at the supply for the bonnet catch you’ll be good. Call Porsche assist, they’ll have a jump pack which will do the job to open the boot and jump the car. Then leave it running and you’ll be ok. You must make sure the trickle charger says it’s charging. Have you not driven it for a while? No - it’s under the Porsche recall for centre locks - it’s been dormant for about 3 weeks.

I have had this, completely dead, had to use physical key to get in. If you follow the instructions in the manual to the letter using the passenger footwell access to get at the supply for the bonnet catch you’ll be good. Call Porsche assist, they’ll have a jump pack which will do the job to open the boot and jump the car. Then leave it running and you’ll be ok. You must make sure the trickle charger says it’s charging. Have you not driven it for a while?

acwh said: Battery is lithium. It has a contactor in it, you can’t just charge it if it’s dead. It’s now protecting itself. Ahh that makes sense.

Monch said: My 992 went dead. lithium battery CTEK did nothing Porsche came out and jumped with a pack which woke up the system. Any jumper pack will do, doesn't have to be lithium Then drove the car for a few miles Then trickle charged Apparently nothing will work until the car receives a jump charge Im sure someone will explain more correctly than me, but that was the gist!! Yep, exactly this!

Discombobulate said: I would trickle charge over night - and hope. But connect to battery not the cigarette lighter. Make sure the mode on the CTEK charger is set correctly too if you have more than one option (AGM in your car I think). Unfortunately the OP can't open the frunk... yet. Lithium adds a new problem, you can't just charge it from flat, but you'll need the frunk open one way or another. If you've got your manual look up "Emergency unlocking of front luggae compartment". There's a procedure for applying 12v to the car via the fuse box in the passenger footwell and then opening the frunk. There is also an emergency release cable in the front left wheel well. You're not going to just reach up and grab it, for obvious reasons, you'll need the car in the air at the very least. I suspect the initial issue was the ignition going to sleep before powering up the charger. You need to connect the charger via the 12v socket and power it up within approximately 30 minutes of turning the ignition OFF. After that the socket is isolated and will not allow charging. HTH Edited by M11rph on Sunday 15th December 17:48

OP Assuming you have the porsche app open it up tap on vehicle details tap on drivers manual type emergency release of bonnet and then follow instructions to open Then Jump!!

Jamassey said: I can’t open the bonnet to get to the battery! Sorry! And you have a lithium battery so trickle won't work if shut down. Call Porsche Assist. They can use the positive post in the fuse box to get power to the battery from a jumper pack as above

Discombobulate said: Sorry! And you have a lithium battery so trickle won't work if shut down. Call Porsche Assist. They can use the positive post in the fuse box to get power to the battery from a jumper pack as above Thanks mate - that’s my only option now.

Jamassey said: I’ve found the emergency hatch in the passenger footwell - Hooked the jump-leads up to a Macan, but to no avail, all still lights out. Curious why after giving it 12v you still got nothing back from any of the electrics.

I had the same problem on the GT3 about 9 months ago. I was able to open the frunk after using jump leads from another car to the passenger fuse box. Then, reconnect the leads to the battery / ground post and start. Im surprised it didnt work in your case. Make sure you have the negative to a good grounding point when connecting to the fuse box, I think I used the driver side door hinge.

Popolou said: Jamassey said: I’ve found the emergency hatch in the passenger footwell - Hooked the jump-leads up to a Macan, but to no avail, all still lights out. Curious why after giving it 12v you still got nothing back from any of the electrics. The accessible post in the passenger footwell ONLY supplies the bonnet catch. Once that’s open you remove the trim and can get at the battery to jump it. As above, good earth key, I also used door hinge.

Popolou said: Curious why after giving it 12v you still got nothing back from any of the electrics. Absolutely nothing - yea weird. Porsche assistance will be called in the morning.

Jamassey said: Popolou said: Curious why after giving it 12v you still got nothing back from any of the electrics. Absolutely nothing - yea weird. Porsche assistance will be called in the morning. Its because the lithium battery has shut down into self preservation mode. It now needs a jump charge. Nothing else will work Its engineered this way to help us Lead/acid/gel batteries of older cars work differently

Hey dont worry mate. I collected a new 911 in 2019 and the battery literally shut down in the showroom! The lithium ones are designed to protect the vital electronic bits but this is quite worrying if you’re not aware of this. You will need a charger that can recharge the battery, otherwise it will need to be charged by Porsche or their Agent. Once done you do need to use the trickle charger. The Porsche o mat Pro is not ideal as you have a thick wire protruding from the door into the passenger footwell to the charge point. IMO and experience its best to buy a lithium CTEK that you can connect across the battery with a solid connection to the battery with quick release connector to the charger. Hopefully you wont be kept off the road too long, mine was done last week so was fairly quick.

Monch said: Jamassey said: Popolou said: Curious why after giving it 12v you still got nothing back from any of the electrics. Absolutely nothing - yea weird. Porsche assistance will be called in the morning. Its because the lithium battery has shut down into self preservation mode. It now needs a jump charge. Nothing else will work Its engineered this way to help us Lead/acid/gel batteries of older cars work differently Yes, lithium cells suffer damage when they drop too low and its own BMS disconnects the load but the circuit to the front lid is not part of that protection circuit. This is what is being discussed.

And when connecting your lithium CTek, a Porsche pro tech advised, must plumb in the negative connector to the 992’s specific negative post and NOT the negative battery terminal. Something about the charge path into the battery ?? Appreciate it was always advised to carry out this method re spark igniting gasses from battery but this wasn’t the reason . I’ve always connected CTek direct to battery but not wanting to be told off and invalidate my warranty, I duly took note

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jonny finance said: And when connecting your lithium CTek, a Porsche pro tech advised, must plumb in the negative connector to the 992’s specific negative post and NOT the negative battery terminal. Something about the charge path into the battery ?? Appreciate it was always advised to carry out this method re spark igniting gasses from battery but this wasn’t the reason . I’ve always connected CTek direct to battery but not wanting to be told off and invalidate my warranty, I duly took note Not sure about this Porsche / lithium batteries but connecting the negative to an earth post, rather than the negative terminal, is standard advice for any type of battery with a management module / sensor.

jonny finance said: And when connecting your lithium CTek, a Porsche pro tech advised, must plumb in the negative connector to the 992’s specific negative post and NOT the negative battery terminal. Something about the charge path into the battery ?? Appreciate it was always advised to carry out this method re spark igniting gasses from battery but this wasn’t the reason . I’ve always connected CTek direct to battery but not wanting to be told off and invalidate my warranty, I duly took note It’s the same on the 991.2…I know lots of people use the CTEK charger via the cigarette lighter etc but I know f k all about these things and tend to think Porsche tell you what to do for a reason.

At the risk of repeating some of the above, attach the charger's positive to the central spade in the fuse box and the negative to the passenger door shut loop. This should allow the frunk to be popped and then remove the cover below the wiper cowl to get at the battery terminals - positive on the battery, negative on the -ve post as per @JonnyFinance Edited by GT3ZZZ on Sunday 15th December 22:39

Looking at the pictures - a tip I got from a US forum when using a CTEK charger to the battery is to use a pair of tin snips to convert the ring connector to a spade connector, so only need to loosen the bolt a couple of turns to connect/disconnect the charger

Great tip and something I do. It’s a proper pain, trying to undo the nut, which by de sign gets tighter further up the thread, whilst leaning across, one hand supporting your weight, the other wielding the ratchet socket. All whilst trying to keep the now loose battery terminal from losing contact. Which can bring a whole world of other hassle !!

Nobody seems concerned that the battery has gone flat after not using it for only 3 weeks?? My 997.2 has sat for well over a month before and never had even the slightest drop in voltage from the battery.

ThunderSpook said: Nobody seems concerned that the battery has gone flat after not using it for only 3 weeks?? My 997.2 has sat for well over a month before and never had even the slightest drop in voltage from the battery. It's had a trickle charger plugged in via the 12V port in the passenger footwell. I think something has gone wrong there and completely drained the battery. Nothing I can do now - Porsche assist arriving in 3'ish hrs. Really apperciate all the inputs though guys, it's been a school day for me. Thx!

3 hours seem a long time ! It will be an AA man in a silver rather than yellow van. When mine turned up he just confirmed what I had told them on the phone and called for a tow truck to recover the car.

Isn’t there a sequence to go though to keep the footwell port open when a charger is plugged in? Issue I have with the Porsche charger is that if there is a power cut, you have to manually reset the charger and then turn ignition on and off.

ThunderSpook said: Nobody seems concerned that the battery has gone flat after not using it for only 3 weeks?? My 997.2 has sat for well over a month before and never had even the slightest drop in voltage from the battery. Porsche Vehicle Tracker fitted, by any chance?

This is an interesting thread, read from post 44 down. https://rennlist.com/forums/992-gt3-and-gt2rs-foru...

This reminds me, some "smart" jumpers/boosters need to detect a voltage when the crocodile clips are attached before they turn on. If the protection circuit within the battery kicks in (breaking the connection), the jumper will not fire up. It's the reason why some have a small button on the jumper pack which overrides this.

Porsche assist got it going (they're brilliant) - but I have all sorts of problems with the electrical now. Also brakes had corroded on. It's now on a truck back to Porker, such is life.

The low battery will cause a lot of fault to show. Once charged and cleared they should stay away. The parking brake discs sticking is common if applied after driving in the wet, or indeed at this time of year when condensation forms. If your garage is reasonably flat there's no need to apply the parking brake, just put her into Park on the PDK. The car might roll a few inches from where you first stop, but it'll stay put then without the pads contacting the discs and so no chance of binding on.

Jamassey said: It's now on a truck back to Porker, such is life. What a pain! As above, a low battery can cause all sorts of seemingly unrelated warning signs - I doubt anything you have showing will be that serious. I can't quite fathom why your trickle charger would cause your battery to drain, that sounds very odd. As others do, I have my CTEK thing permanently wired in - mine's on a long cable and the female end sits in the 'frunk'.

jonny finance said: how have you fastened it to the negative with the nut? I`ve done this for now, after all sorts of issues with 12v footwell port. I could even get it to stay on for a fortnight then it would turn off

Hi. In your CTek charger kit, should be adaptor lead - has small 6mm ringlets. As described earlier in thread, nip em with snips and then you can slide the ring/bayonet in place without having to undo terminal nut

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I have that. So when you`ve cut it you just push it on the terminal? So you have to cut it a little smaller than the bar so it snaps on and holds in place?

Just undo the nuts a couple of mm slide on and bolt down.

jonny finance said: Do you leave the CTEK connector like that when driving? Have thought about doing this myself but wondered if there's ever a world where the wire could get caught in the wipers & cause damage. Or even having a way to connect to battery exposes security issues

SV_WDC said: Do you leave the CTEK connector like that when driving? Have thought about doing this myself but wondered if there's ever a world where the wire could get caught in the wipers & cause damage. Or even having a way to connect to battery exposes security issues You can buy a long lead (I have one) which travels directly into the frunk and lies coiled in there when not in use. I have the bonnet up when charging which reminds me not to drive off with it attached - the light turns off in there when the car locks.

NDA said: I have the bonnet up when charging which reminds me not to drive off with it attached I have a large red Remove Before Flight banner from the space shuttle programme (via eBay) attached to the cable which serves a similar purpose

In this instance, I use the extension, rerouting away from the wiper mech, across to nearside then popping up. Leaving bonnet up a good call but not if you’d rather lockup shop

The CTEK will not be sufficient to keep the battery fully charged over a prolonged period of time. (I have a 992 GT3 Touring).The lithium battery will “shut down” when it falls below a certain charge despite the fact that it is connected to a CTEK lithium charger. Therefore always leave the front trunk open in order to be able to access the battery if parked for a longer period in a garage and then use jump leads. Otherwise it will lock as described and you need to open the trunk via the fuse box. I occasionally leave my car for more than 3 weeks in the garage and have bought a starter battery pack which I can use to jump the car or alternatively to connect to the pull-out contact in the fuse box to open the trunk. It’s a pain but once you have tried it once or twice its pretty easy to perform.

Sounds like maybe you have an iffy battery. Had a few 992’s with Lithium and can be left for extended periods without even a charger connected. My pal has left his GT3 for over 3 months without charger or issue - minimal volt drop and starts zero issue. Hes too tight to buy a CTek or pay the electric to run it !!

I have had it checked at Porsche in Munich and they confirm the issue that the battery goes into “protect mode” at a certain low level voltage and then is impossible to wake up and needs to be jumped. Maybe it’s the Porsche App and remote diagnostics that drain the battery. But after having bought a Starter Pack Battery I’m not too bothered.

Think this thread is useful - in future I will leave my boot open. Sounds a pain if battery does shut down.

I have this featherweight and tempted to fit. It has a great sophisticated feature where you can access the BMS remotely via your phone. Can read individual cell status , put into power save and theft mode etc Top tier LiteBlox motorsport battery, mega expensive and infinitely superior to the standard 992 issue lithium…. But no doubt if fitted would completely invalidate the car warranty

There will soon be a thread about dead battery consequences on the 992.2 GTS. The small 400v battery is used to start the engine. “On T-Hybrid vehicles, the engine is started via the 400v battery. If the charge level of the high-voltage battery falls below a defined threshold value, the jump-lead starting can only be carried out by a specialist workshop”

gtsralph said: There will soon be a thread about dead battery consequences on the 992.2 GTS. The small 400v battery is used to start the engine. “On T-Hybrid vehicles, the engine is started via the 400v battery. If the charge level of the high-voltage battery falls below a defined threshold value, the jump-lead starting can only be carried out by a specialist workshop” Which is yet another reason to run away from the latest tech cars. Every new generation gets dafter and dafter.

As well as the one shown above, CTEK also do a version of the battery connector with lights that show charging status (flashing green) and indicate battery level, in case you have the CTEK box tucked away somewhere and the 2.5m connector extension CTEK 56-629 Indicator eyelet M6 (link) Edited by mikef on Thursday 19th December 17:18

gtsralph said: There will soon be a thread about dead battery consequences on the 992.2 GTS. The small 400v battery is used to start the engine. “On T-Hybrid vehicles, the engine is started via the 400v battery. If the charge level of the high-voltage battery falls below a defined threshold value, the jump-lead starting can only be carried out by a specialist workshop” I wonder if somebody will supply a 400v trickle charger ... just joking ! But surely Porsche must provide for these cars not being used for a while ??

jonny finance said: Went to do this this afternoon, only to find the battery on my Carrera is the other way round, so the CTEK won’t stretch from the grounding point on the left side, to the positive side on the battery on the right. Guess it’s back to using the cigarette lighter input?

Bobtherallyfan said: Went to do this this afternoon, only to find the battery on my Carrera is the other way round, so the CTEK won’t stretch from the grounding point on the left side, to the positive side on the battery on the right. Guess it’s back to using the cigarette lighter input? Is there a bolt you can use as ground nearer the battery - something connected to the body like that black bar than runs across horizontally?

There is an unused M8 threaded hole in the near side top mount pillar that is normally used.

Bobtherallyfan said: jonny finance said: Went to do this this afternoon, only to find the battery on my Carrera is the other way round, so the CTEK won’t stretch from the grounding point on the left side, to the positive side on the battery on the right. Guess it’s back to using the cigarette lighter input? Is your battery meant to be the other way round? If it is, you could always connect the CTEK negative lead to the battery negative, though that might mess up any calculations the car does to decide whether stop/start is allowed, if your car has got that.

jonny finance said: Went to do this this afternoon, only to find the battery on my Carrera is the other way round, so the CTEK won’t stretch from the grounding point on the left side, to the positive side on the battery on the right. Guess it’s back to using the cigarette lighter input?

Mines the other way around too I pulled the Ctek cable apart, red and black to the plug Its designed to pull apart along the join

Having only last week had the issue of a completely dead lithium battery in my 2022 Turbo S I managed to bring it out of its dormant mode without the need for Porsche Assist or the AA/RAC. Once you've managed to get into the car using the blade hidden in the key fob and reached over to the passenger side to pull out the positive jumper thingy, you then can't open the passenger door, so have to connect your trusty booster (I have a Noco) to it and the negative to a random piece of wire that then allows you to reach the hinge or latch of the open driver's door. Applying power gives you enough to pop the bonnet and you can then disconnect everything. Be careful that you are wielding a random wire that has power on it... Once you have the battery exposed, attach your booster of choice and leave it on for a few minutes to bring the lithium battery out of its sleeping state. Then connect the Ctek and leave it for as long as you can. I left mine for 24hrs before then trying to start the car. It started and was absolutely fine after all the silly electrical messages had cleared themselves. If you're in a rush I imagine the booster would provide the power you need to start the car, but be aware that a quick drive round the block won't be enough to charge the battery and stop it from going dormant again soon after. You need to drive for 2-3hrs to really charge it enough. Get a Ctek, they're absolutely worth it.

Good advice. If I can add another little tip. If you plan a trip after having recharged the battery with the CTEK unpluck the CTEK the night before you plan to leave just to make sure that your car has sufficient power to start up and to rule out that if the battery is faulty and cannot hold any power.

I've only just read this today and probably could have saved the OP the hassle of the recovery. To get the bonnet open attaching a 12V power source is just part of the procedure you still have to use the bonnet release on the remote once the 12V source positive lead has been attached to the pull out terminal and the negative lead to a good earthing point. Porsche in their "wisdom?" of designing the mechanical unlock and bonnet release procedure for left hand drive cars means that this in itself is a big hassle. The passenger door cannot be opened so as happened to me with my wife's 718 next to my GT3 in my garage, I had to make up two very long leads to reach from the 718s battery to the terminal in my GT3. Once you have got that bonnet open and removed the cover then assuming, you are using a CTEK Lithium XS Charger attached to the positive and negative leads as shown elsewhere in this thread, hold the Mode button for at least 10 seconds this will send a 12V pulse to the battery which will close the internal battery protection relay and the CTEK will then detect the battery and start to charge it. I had the exact same problem with my 992 GT3 and it was only after I read the CTEK Lithium XS manual that I discovered this procedure. For info the Lithium Battery will open it's internal circuit breaker thereby disconnecting itself from the car and any charger connected in any of these conditions: 1. When the state of charge is below 15% or the voltage drops below 10V 2. When the voltage exceeds 16V 3. When the voltage drops below 6.5V or exceeds 18V 4. When the battery overheats or there is a short circuit. If it occurs as a result of 1 or 2, the reset procedure can be used but for scenario 3 it will not reset and you have to get a new battery as the battery has been damaged. For scenario 4 if the battery has overheated as a result of a short circuit then it's probably damaged and needs to be replaced too. As an aside I bought a small 12V power bank, made up a long lead set and keep both in the glove box of my 992 Turbo S (also has Lithium battery) which replaced the GT3, I've also got a cordless CTEK CS Free charger to cover the scenario if this were to happen away from home. The CTEK CS Free charger does not have the same mode to close the Lithium battery internal circuit breaker but the small 12V power bank can do that or if that has lost charge then the CS Free has a USB output which can recharge the power bank. It's still a load of faff but a lot less than waiting for recovery to turn up especially if you are away overnight or abroad.

Fantastic in-depth details, and no doubt all learnt the hard way ! I remember way back, my Mk1 Golf GTi had its original battery still in place and working after 20 odd years. And when it eventually did start to fail, that prolonged decline took another few years - just using jump leads when required. Batteries and just about everything has a very short working life nowadays!