Remote Start in extremely cold temperatures
Driver
Joined: Nov 2014
Posts: 75
Likes: 6
From: Illinois
I too live in Chicagoland and see no reason to have remote start on my 2015 RX450h. Even when it was -14F, my seat heater and engine were up to temperature before I was out of the subdivision. Besides, the Lexus manual tells us not to start the engine and sit until it heats up. That is what they have the faster heat up on the newer model than the previous models. Long times in idle is hard on an engine that uses 0-20 oil.
No, I don't play soccer!
Joined: Jul 2009
Posts: 6,652
Likes: 177
From: NJ
COPAPILOT, I've heard the newer RXhs heat up quicker. It would be interesting to know why. Since you mentioned temperatures. RES is limited to -22 F and above. Any colder, well I'd start questioning sanity for living in a place like that, LOL! It came in handy the other day when everything was covered in ice. Sitting inside was better (and safer) than going out to scrape it off the windows. The handles were also frozen. In summer I use RES to cool down the 450h when it's super hot and humid. So it's not just useful in winter.
Lexus Champion
Joined: Feb 2004
Posts: 1,973
Likes: 55
From: Ohio
3RX450h warms up quicker because of the Exhaust Heat Recovery System that was added in our generation:
Originally Posted by Toyota Pressroom
Calling All BTUs
Another key to improvements in fuel economy comes from the Exhaust Heat Recovery System. An important part of the hybrid control strategy is to stop the engine when it’s not needed, for example in low power demand conditions in city driving. But in winter driving, engine heat is needed to warm the interior cabin and demand on the electric drive motors will be naturally higher in these conditions, especially during warm-up. When temperatures drop below 0° C, battery output is also reduced and drive motor performance suffers accordingly.
To counter this challenge, Lexus developed an efficient system that recovers exhaust heat to quickly raise coolant temperature during warm-up. This allows the engine to stop sooner, helping to improve fuel economy during this phase. For example, testing at -5° C on a typical driving pattern (below) showed that the engine could be stopped a full 1,000 seconds (over 15 minutes) earlier than the previous model.
Exhaust heat is recaptured from the exhaust pipe just downstream of the catalyst where a recovery unit is mounted directly on the exhaust system. A thermostatically controlled valve forces part of the exhaust gas to re-circulate in a chamber, heating the surrounding coolant quickly. A spring in the valve allows it to open during full acceleration. When engine coolant warms sufficiently, the valve opens to allow exhaust gas to bypass the heat recovery system.
Another key to improvements in fuel economy comes from the Exhaust Heat Recovery System. An important part of the hybrid control strategy is to stop the engine when it’s not needed, for example in low power demand conditions in city driving. But in winter driving, engine heat is needed to warm the interior cabin and demand on the electric drive motors will be naturally higher in these conditions, especially during warm-up. When temperatures drop below 0° C, battery output is also reduced and drive motor performance suffers accordingly.
To counter this challenge, Lexus developed an efficient system that recovers exhaust heat to quickly raise coolant temperature during warm-up. This allows the engine to stop sooner, helping to improve fuel economy during this phase. For example, testing at -5° C on a typical driving pattern (below) showed that the engine could be stopped a full 1,000 seconds (over 15 minutes) earlier than the previous model.
Exhaust heat is recaptured from the exhaust pipe just downstream of the catalyst where a recovery unit is mounted directly on the exhaust system. A thermostatically controlled valve forces part of the exhaust gas to re-circulate in a chamber, heating the surrounding coolant quickly. A spring in the valve allows it to open during full acceleration. When engine coolant warms sufficiently, the valve opens to allow exhaust gas to bypass the heat recovery system.
Lexus Champion
Joined: Feb 2004
Posts: 1,973
Likes: 55
From: Ohio
Rookie
Joined: Jan 2014
Posts: 63
Likes: 3
From: Pa
Minus 8 this morning
Started my hybrid this morning at 4:30 ( twice at 15 minutes)with temps of "minus 8". With the new optima yellow top battery, things went as expected. The Fortin bypass module I installed last year has worked well too.
Cannot put a price tag on jumping into a warm car at 5 am.
Gampa
Cannot put a price tag on jumping into a warm car at 5 am.
Gampa
No, I don't play soccer!
Joined: Jul 2009
Posts: 6,652
Likes: 177
From: NJ
Definitely agree, Gampa. It was 0 when I got into the 450h this morning with the wind chill making it feel like -23. But one round of RES took off the edge. Just wondering, have you had words with Punxsutawney Phil? I heard NH has an arrest warrant out on him. MA is probably next.
Driver School Candidate
Joined: Mar 2015
Posts: 7
Likes: 0
From: Florida
Remote Start 2015 450h
My 2015 450h is 6 months old and the Auto Start stopped working.
Car would start then after 10 seconds turn off.
Dealer reset ECU no luck. Re-programed the ECU and that fixed it. Only 5000 miles on the car.
Auto Start works but Lexus designed it to shut off if any door is opened so no one can steal the car. Then you get in and restart the car. Duh! Auto Start works with your FOB. If you Auto Start your car and walk away the car goes crazy.
OK Lexus, Can we get a Program Update so the car does not shut off?
Without the FOB, the car shuts off after ten minutes, so how are they going to steal your car?
Car would start then after 10 seconds turn off.
Dealer reset ECU no luck. Re-programed the ECU and that fixed it. Only 5000 miles on the car.
Auto Start works but Lexus designed it to shut off if any door is opened so no one can steal the car. Then you get in and restart the car. Duh! Auto Start works with your FOB. If you Auto Start your car and walk away the car goes crazy.
OK Lexus, Can we get a Program Update so the car does not shut off?
Without the FOB, the car shuts off after ten minutes, so how are they going to steal your car?
Driver School Candidate
Joined: Mar 2007
Posts: 4
Likes: 0
From: WI
same problems with 2015 rx450h
Found this thread in a search. My 2015 RX450h has the exact problem the OP had. Sub zero temps and the engine will crank and immediately shut down. Above zero and all works fine. I guess The problem still exists with the ECU.
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