Herbie

Wow Marci, that sounds very frightening and I hope everyone in the car is alright. I'm afraid I haven't got an answer for you because I've never heard of this happening either. I presume you had to report all this to your insurance company so what have they said about this strange event? Only a guess but that would suggest to me that the hybrid system had some sort of catastrophic failure, because "Ignition on" is the message that appears when the car is in Accessory mode, rather than the "READY" light you see when the car is in hybrid mode. Given that it's a 2022 car it should still be within the manufacturer's warranty period, so surely they can't just wash their hands of it all? If you don't get any further with the dealer, contact Lexus Romania. I hope you get a speedy conclusion that is to your satisfaction my friend.

If you look at the chart below you'll see that 11.4V is quite a big problem:

It doesn't matter. 12V is 12V whether at the front, back, top or bottom and they're directly connected to each other anyway.

You're very welcome Paul and the Gooloo lookslike a good choice. No need to worry about your battery, these jumper units work on all batteries. I've got a Tacklife T8 and I've used it on lead-acid and AGM without any problems. EDIT: One thing I would say is to get one with a digital readout of how much charge is in it. Mine is reading 90% even though it's been sitting in the car (unused) for a good 9 or 10 months. Of course, the idea is that you don't get caught out so I do try to remember to charge it every 6 months or so, and now that I've realised that I'm late, I'll do it this very afternoon.

Safe, yes; useful, no. The cigarette lighter sockets are only energised when the car is on, which means that when the car is off (as in the case of a flat battery) there is no pathway for the jump starter to get power into the 12V battery.

When I look at National Tyres and search for Michelin in 235/55/20 nothing comes up. All they're offering in that size are 2x Bridgestones, 2 x Pirelli, 2 x Continental and 1 x Hankook.

Completely different technology. The way Lexus decided to do things was to use a pair of 12V relays as a safety interlock. If the 12V battery has enough juice to operate the interlock it energises the hybrid system, but if not, the interlock doesn't operate and so no access to the hybrid system and/or battery for the 12V to 'pinch' a bit of power.

You probably need to get on your back and stick your head under, then look straight up towards the top of the dash.

Is that with the 20" wheels Phil, or smaller ones?

I've heard a couple of horror stories about the TPMS sensors being broken and/or calibration problems when an independent tyre place has been used, so I was thinking of getting the dealer to do them but what's the procedure? Do dealers have a limited range and you can only choose from those, or can you say that you want x,y, or z even though the dealer doesn't stock them? Do dealers source them for you and have them delivered to the workshop, or do you have to source them yourself and take them to the workshop yourself? My first choice would be Goodyear Vector 4Seasons, closely followed by Michelin Cross Climates, but the 20" wheels seem to limit choice somewhat.

You should never attempt to start a conventional car from a hybrid, but you can jump start another hybrid from a hybrid. This comes about because a conventional car's starter motor can draw upwards of 300A when cranking the engine and that power usually comes from the donor alternator, hence why the donor car needs to have its engine running. Our hybrids don't have an alternator. We get our power from a DC/DC converter, which is fed directly from the traction battery (somewhere in the region of 280V-300V depending on model and variant) and reduces the voltage as necessary, ie, about 14.5V to charge the 12V battery; 48V [IIRC] for the power steering and so on. Our hybrids only need about 20A to get the car into READY mode and the max output of the DC/DC converter is somewhere around 100A. If it was called upon to supply 300A to a conventional starter motor, I can imagine a big bang and all the magic smoke that makes it work would escape into the atmosphere In reality I'd hope that there's some current-limiting circuitry to prevent that from happening, but us electrical types do like to see a good arc flash and a decent bang never goes amiss

Disconnect the battery. You may have to reset one or two things but at least the battery won't be damaged, which might happen if it goes flat and is left flattened for any length of time.

The 450+ is the plug-in variant isn't it? If so, I know nothing about them so I may or may not, be talking rubbish. To me, EV mode suggests that the car is drawing from the batteries but nothing is going back in to keep them topped up. Try again but just not in EV mode this time.

Because it's an electrical problem and having been in the electrical / electronics field all my working life, I do have a certain knowledge and understanding that I hope may be useful to people with those types of problems. This is true but Lexus will not do anything retrospectively to the cars already out 'in the wild' so your continual complaining will never be of any benefit to you yourself. Great, so your problem is solved and you have no further need to complain anymore. Sorted

If there's a clicking noise then I'll almost guarantee that your battery is flat. As you press the start button, power is passed to the starter solenoid, which is basically an electromagnetic plunger-type switch. The battery has enough power to energise the solenoid and pull in the contacts, but when those contacts meet and power flows to the starter motor, there isn't enough power to turn it and the voltage drops like a stone. As the solenoid releases the contacts the voltage rises high enough to energise the solenoid and the whole process just keeps repeating. It's commonly known as 'solenoid chatter' because of the ticking noise it makes as it pulls in and then immediately releases again.