Herbie

Use Android Auto (or Apple CarPlay depending on what your phone is) where you can use my personal favourite Waze, or Google Maps, Sygic, TomTom and HereWeGo amongst others (at least on Android).

When you press the start button the computers boot up and bring the hybrid system online, at which point you'll get the green READY light and it'll stay like that until you switch the car off.

As Malcolm said above, a replacement alternator is usually done on an exchange basis, so you send yours in and get a refurbished unit in return. If you can't find anyone with the specific one in stock then you could send yours for repair and refurb. I live within a couple of miles of this place and you could send it there or there may be a place closer to you who does it. This is definitely the way to go though; no way on earth would I be buying a new unit from Lexus.

It may be a Lexus but it's also just a standard petrol-engined car like thousands of others, so any OBD scanner will do the job.

This may be handy for reference:

I've just realised that further up the thread Rayaans states that the battery is 32Ah, which alters things significantly. 32Ah divided by 0.05A = 640 hours from fully charged to fully discharged. That's just 26.66 days or 3.80 weeks! And remember, that's a theoretical maximum - in reality you'll get much less than that.

Hmm...but is it?......Really? The problem with the 12V battery drain is that it isn't really a fixable problem, more a design fault that shouldn't ever have got off the drawing board. I don't know what capacity the 12V battery is in these cars but I'll assume a couple of things for the sake of this example. All batteries will exhibit some level of self-discharge anway, but we also need to take into account the quiescent current draw when the car is 'asleep'. This is the amount of current drawn for things that need to be kept alive, like the intruder alarm, the radio presets, the seat memory and so on. Modern cars take around 50 milliamps (50mA or 0.05A). So, let's be generous and say that the 12V battery has a 50Ah capacity. This means that it can supply 50A for one hour, or 25A for two hours, or 12.5A for four hours and so on. Let's also assume that it's brand new and fully charged, so that: 50Ah divided by a draw of 0.05A = 1,000 hours from fully charged to fully discharged. That's 41.66 days or 5.95 weeks. However, the battery will not be capable of starting the car well before it's fully discharged, so in reality you'll get a lot less than that 1,000 hours and remember that I assumed a 50Ah battery. If the capacity is lower then you'll get less again. Also remember that as a battery ages, its capacity will drop so again, shorter time between charges if it's not used enough. This is how the car was designed, so you could say it's a design problem or you could equally say that hybrids and/or EVs are just not suited to some people's driving habits. They need to be used on a regular basis or kept on a trickle charger when not being used.

You're very welcome Victor.

If the lighting stalk on the steering column is set to 'Auto' then surely the change from day to night mode should happen automatically?

This is from the workshop manual of model years 2009 to (I think) 2011 so it may not be exactly the same for your 2015, but I would imagine it would be close enough for what you need.

I'm no mechanic but I believe that you need Techstream to reset the brake actuator or something. Maybe something like Carista or OBDFusion can do it these days but originally you needed Techstream.

No idea but why sign out? I've been almost constantly signed in for years.

You may well be right, I honestly don't know - but there must be some reason why they don't include rear DRLs during the factory build of any car, be that Lexus, Ford, Jaguar or whatever.

I'm no mechanic but you have to weigh the risk against cost of repairs if anything goes wrong and, personally, I wouldn't risk it.

I'm not sure but would say no, simply because it would look like you're pressing the brakes.

I got a set of these switchback white/amber LEDs for my RX300 when I had it and they were great. All it needed was a single 12V relay wiring in and that was easy. Highly recommended if your car is suitable for these.

Not sure I agree with that Malc. Remember that Lexus/Toyota don't manufacture batteries, they just buy them in from people who do manufacture them. This means that they are consciously making a decision to buy low electrical capacity batteries. Higher capacities of, say, 75Ah, 100Ah and even 120Ah are being manufactured and are readily available but Lex/Toy just choose not to use them.

No, no and thrice no. You cannot do any damage by connecting to the negative battery post rather than an unpainted bolt/nut/screw/bracket etc., etc., apart from one caveat. Under certain conditions a battery can emit hydrogen gas and so create a risk of explosion if a spark were to ignite it. This is why the advice is to clip to an earth point away from the battery itself, so that any sparks generated will not be in close proximity to the gas cloud (if there is one*). However, from an electrical point of view, there is no difference whatsoever whether you connect to the battery terminal itself or to some unpainted nut/bolt etc., etc., at the front, back, top or bottom of the car. Not one jot of difference at all. *In more than 40 years of hobby spannering I have never personally seen or heard of an explosion being caused in this way, nor have any family or friends.

It's 'mission critical' because right at the start of the whole process there are a pair of 12V safety interlock relays that have to be operated before access to the hybrid system is allowed. Not enough power to operate the interlock means no car.

That's correct Len, yes. It will fail to start even a hybrid car long before it reaches full discharge.

The need is due to the laws of physics. A 50Ah battery means that it can supply 50A for one hour or 25A for two hours, or 12.5A for four hours and so on. If we assume a brand new and fully charged battery with 50Ah rated capacity and a parasitic drain of 50mA, the time from full charge to full discharge is 1,000 hours or 41.66 days, or 5.95 weeks depending on how you look at it and that's it.

No, but you can get your own back

Smart Tuning fitted it but who made 'it'? Is it a BeatSonic unit, or a Lexion, a Teyes, a RoadTop or a Grom Vline2, or something else altogether?

Lexus navigation is abysmal, which is why there's always lots of talk about Android Auto or Apple Car Play, because of the superior mapping and navigation available. If you really insist on torturing yourself by using the Lexus nav, you can use postcode search on Page 2 of the nav screen.

You need to read the OBD codes (if any are flagged) then tell us what they are. These codes are starting points for further diagnostics and help to point us in the right direction; without them all anyone can do is make random guesses.