I haven't checked the forum for a while, and I was wondering if in the meantime someone found any trick for forcing EV mode on the RX400h.
In fact, I had in mind that someone was trying to add a button or something, possibly through the OBD connector (can't remember exactly) for forcing the vehicle to not turn the ICE on.
The caveat being that it would have required a judicious usage, keeping the battery status monitored to avoid killing it, but that's sort of obvious.
But I tried some searches, and found nothing... Am I dreaming of it, or what?

 

You are dreaming!....sort of. There was some talk and I came across it on the internet of someone trying to achieve that some years ago. But I haven't heard about it since. To me the battery is just too small to try to run it in EV mode. I had an crazy engine failure because of (from bad oil) which cause the car to go into limp mode on ev only. In short The car did not get very far or fast on battery only.
I am waiting for the new lexus line of plug ins to get a little cheaper (or become cheaper as a used vehicle) to get that feature built in.

 

Is anyone possibly aware of news on this subject?
I'm well aware that on the 400h the electric range is negligible, but for space reasons I must enter the place where I store my car in reverse.
So, being able to force EV even just for a minute or so would allow me to avoid having gas exhausts inside it upon every departure and return...!

 

You can't control it. V light on the accelerator as you reverse. Turn off all peripheral draws on the battery ie air con, fan, lights etc. Maybe then you'll get into your garage EV only. But regular IE drivers can reverse into garages without asphyxiation.

 

I'm not sure how forcing EV mode would help in your case. As far as I'm aware there's no mechanocal reverse gear in a Lexus ecvt, and so reverse is always driven by the electric motors. The ICE would only then kick in if the traction battery needs charging. I would assume that a forced EV mode would then either allow the battery to drop below recommended levels, or cut the power if the battery drops below that level.

 

That's also my understanding.
OTOH, the ICE kicks in whenever the car decides, and sometimes that does happen also in reverse - even regardless of the traction batteries charge status!
Up to a point, at least: of course the ICE automatic start is more likely to happen when the traction battery is at the last purple bars, rather than the top green, but you have zero control on that anyhow.

That said, I'm well aware that EV mode on the 400 couldn't last for long, but I'd use it for just a minute or two at very slow speed, so hardly a battery killer.
And it's not like the 450h can last much longer in EV, but they did include the functionality in it anyhow, so I don't think to be alone in thinking there's a use for it...
...but... Hey-ho! if it's impossible to retrofit that, I'll live without it!

 

I'd like a switch to engage EV mode so I could just pull into the garage from the driveway or the opposite. The ICE "just" turns on in either case. Battery charge does not matter here.

I think the car logic is to start heating up the emissions equip (required by EPA then) because it thinks it's going for a drive.

There was some hope back in the day that the car had an unused plug we could just plug a switch into to force EV mode. Maybe the Prius had it? I don't know that anything ever came of it. Newer cars came along...

 

car is too old to this feature.

 

Good point. Perhaps they did include it in the 450h due to demand.