Hello all. I have noticed that with the colder weather my 450h has been turning the gas engine on when I start to reverse. i have about a 20-25 minute commute to work and by the time I'm backing into my spot the engine is normally fully warm. About half the time now the engine will kick on when I start to back up. I -think- this is normal as the brand new hybrid highlander I test drove did the same thing. Does anyone know what causes this? I had a rx400h before the 450 and do not remember this happening. Thanks for any insight.

 

This happens to me with my 2013 RX450h upon occasion and is not a concern.

 

Maybe for the heater need if the weather is cool/cold? Could be a defective sensor ?

 

If the air temp is cold, the engine will often start simply by taking your foot off the brake, even if it is warm. Going through drive-throughs in winter, I've learned to try to release the brake only enough to creep forward. If I release the brake fully and coast forward, the engine will start and stop 10 times before I get to the pickup window. I suppose I should try EV, but I never bother.

 

This happens on my 14RXh as well - I'd trust the engineering built into this car.

 

It's perfectly normal. When starting my 2010RX450h in the garage on a cold morning, the ICE would start when backing out about the time the whole car was out of the garage, sometimes earlier.

 

The OP said the car is warm when it does it, not backing out of his garage.

As you know reverse is electric-only, so I would suspect the car thinks the batteries are not sufficiently charged so the ICE kicks in.

 

The gas engine on my 450h also kicks on maybe half the time when reversing. Haven't taken a look at the battery level to see where it's at. Maybe next time. But it's pretty normal.

 

Technically speaking, forward is electric as well. The only difference, if the ICE kicks in, MG1 has to work harder to compensate for the rotation of the ICE, making MG2 rotate in the opposite direction, along with wheels.

 

As I learn more about these cars, I am more and more impressed with the technology and engineering. I too, trust them. However, if it continues to be a concern, you could always put it In EV mode when reversing. My dealer is very convenient to me, and I've developed a pretty good relationship with my Service Advisor. I'll sometimes drop by for a cup of coffee and a muffin, and ask him questions like this, or just send him an email. He usually goes out to check with the tech, and comes back with a great answer that keeps me comfortable. Usually, "it's working as designed", but with an explanation to help me understand why.

 

That's great Woody. I do the same with my SA. If she doesn't know, she'll grab someone who does.

Your post reminded me of a time I took my parents to a Lexus driving event with most models and their competitors many years ago. They had the LS600 there. My father spent more than an hour bending the ear of the poor Lexus rep near the car trying to get an answer about how the engine knows when to make the switch from electric to gas, among other things. He can't settle for 'it just works.' But we know it's well proven technology.

 

FWIW, I ran several errands this morning in my 2013 RX450h and tried to keep a close eye on the hybrid/battery display in center of the dash, and when my RXh was turning the ICE on, as I was backing up. The four scenarios were as I sorta expected:

• Backing out from my garage this morning, the RXh started on battery only, but the ICE kicked-in before I was at the end of my relatively short driveway and before I shifted into Drive.
• At 2 of my 3 stops, upon backing out of the parking space, the RXh stayed on battery only until I shifted into Drive and was going 7-8MPH out of the lot.
• At the other stop, the RXh kicked the ICE in while I was backing up like it did in my driveway earlier.

I've never had a hybrid issue, so I'm gonna continue letting the computer manage my RXh, and not try to second guess it. It and the Lexus Engineers are a lot smarter than me as to what my RXh needs and when, so I don't have to think about it. Perfect!

 

How do you know when it's truly cold? (Like today)

The "Ready" light doesn't come on until a second or two AFTER the engine starts.