When I leave home I have to enter a nearby busy road where the traffic is going 50-60mph. Several times the engine has bogged or lost power when starting to enter traffic. It only does it when the engine is cold. When I took it in for my first service I mentioned it and was told there were no codes indicating a problem. The technician took it for a test drive and could not duplicate the problem because the engine was warm. I thought the electric motor was supposed to kick in and eliminate any turbo lag or bogs. I tried using sport mode to see if that would help but it didn’t make any difference. I would appreciate any input on this issue, particularly a fix.

 

How "cold" are we talking here? In the morning I'll usually start the engine and wait until the idle drops before I put it into gear and drive away. No lag issues.

 

I don’t wait for the idle to drop and it’s about 3 blocks to the busy road. How long does it take for your idle to drop? If it’s not that long I’ll try it. It’s a definite safety issue not knowing when the engine is going to bog.

 

Try monitoring the energy flow screen on the center display. (press the Car icon then scroll down & select Energy Flow)
See if the traction battery is weak when your issue occurs. Should have at least 1/4 charge.

Never experienced an issue as you describe.

++++++++++++

We often need to quickly accelerate onto a 40MPH road one block from the house (~2 minutes running time) because tall hedges block views of oncoming traffic!

 

@mack24 was your car in Eco mode? I lost power just this past weekend and gain back power maybe three to six seconds after and I was in Eco mode. Yes I waited to put the car in drive after the idle drop during cold start. Luckily I made it past incoming traffic into the center lane and I was waiting to merge but I lost power to I went back to the center lane. I wont bring it back to Lexus as I am 100% sure they can't duplicate the problem.

 

Traction battery shows about 60% charge. I have never used eco. I did try sport and it still had the problem. Just did it again yesterday morning. Seems to be happening more often. I hope it will show a fault code when I take it in for 12 month service.

 

Hi-
I am having the exact problem with my RX500hFSport (2023)
Did you ever get a resolution? The mechanics are unable to replicate the issue but it exists.
Thanks
LMNYC

 

I'm wondering if what is happening here is simply an engine protection feature, limiting boost while the engine is cold. I've always heard that it can be harmful to a turbocharged engine to apply full throttle when the engine is still cold. This sounds like the vehicle computer could be reducing throttle to save the engine

 

Hi-
I am having the exact problem with my RX500hFSport (2023)
Did you ever get a resolution? The mechanics are unable to replicate the issue but it exists.
Thanks
LMNYC

 

2023 rx350h had the same problem that bothered me for a year, and I couldn't solve the problem after going to the dealer four times. But this problem has disappeared recently.

Maybe you can try my method.
1：Don't add bp gas

2:close Parking support brake

I'm not sure which one, but I only did these two things that day, and now there have been no problems for more than three months.
Forgot there was another one closed.

FRONT CROSS TRAFFIC ALERT

 

Correct you should not have that logo of car with open circle around it in orange as then it using all those dumb proactive safely bubble system. Meaning even if you take a turn at good amount speed it will break the wheels to help assist the corning, or if your someone that drives close in front of you it will be slowing you down your pedal inputs. Same with Front Cross Traffic, this is all under this proactive driving nonsense bubble.

It is really pointless this garbage we are forced pay for, the only one that I find helpful is pre collision and one that protects you when parking. Everything else I would shut down.

 

Just took my 500h in for 12 month service today. Service writer said there is still no acknowledgement of the problem by Lexus and therefore no fix. I have used sport mode for the last ten mornings and that seems to almost eliminate the problem. I did have one small bog. I can live with that fix because it’s easy to switch modes. Please let me know if a factory fix shows up.

 

More likely a transmission issue IMHO. Lord knows that transmission has had issues.

 

Here is a Topic to read about trans issues:


https://www.clublexus.com/forums/hyb...versing-2.html

Ask the dealer to apply TSB L-TT-0328-23 if your RX's manufacture date is before fall, 2023.

If that helps, PLEASE post back. <-- Yes, it requires a replacement transmission and a software upgrade.

 

A GR Corolla owner discovered that the boost is severely limited when the engine is cold. I'm pretty sure this is to prevent engine damage. I'm guessing something similar is happening with the RX.

GR Corolla max boost at different oil temperatures:
<50c (<122f) = 5psi
50-60c (122-140f) = 7.5psi
60-70c (140-158f) = 10psi
70-80c (158-176f) = 12.5psi
Over 80c (>176f)= Full boost