biker1

Within weeks of my buying this lovely car (bought new in January 2014), from time to time, when proceeding from a full stop (at a light, or stop sign), I roll into the path of oncoming vehicles but when I try to accelerate, there is absolutely no response for perhaps 2 – 3 seconds. My natural reaction to this delay is to pump the throttle, but because this is a drive-by-wire car, this has absolutely no effect....and then the power comes back and the car accelerates normally and I don’t get run over and life goes on. This occurs sometimes several times a day and sometimes on consecutive days and them sometimes there are several (5 – 10) days between incidents.

I have complained three times now, to my local (and selling) Lexus dealer, in London, Ontario, Canada without any solution. The first two times, they said that they’d never heard of such a problem. However, the 2nd time, they sent me out with the Shop Foreman for a 20 minute drive (without experiencing this problem), who then hooked up their diagnostic system (which told them what, I do not know) and his opinion was that probably the TRAC system was interfering, but this is not a system that can be adjusted for sensitivity....and probably it interfered because one or more of the tires was on a wet or sandy or otherwise slippery surface and the system was reacting to wheel slippage (and I responded that at no time were these the conditions....it was always when the roadway was completely dry, etc.)....and the 3rd time (mid-October 2014) they said that a couple of other customers had also reported this problem, since my last visit to complain, but they have not been able to find either a cause or a fix for it, but they will keep looking and get back to me ASAP....and to date there has been no further contact.
biker1

spwolf

without them experiencing, it is hard thing to diagnose... you need to escalate this further if dealership is not helpful enough, to corporate.

i dont think i saw any other member experiencing the same issue.

ItzFilyO

U can try resetting the ECU by leaving the battery unplug for an hour or overnight and let the car relearn everything again.

jkeller

Do you brake with your left foot? If press the gas with your other foot even slightly on the brake, the car won't move. This is programed into the car's computer. I've done it myself twice. It came about after a very bad Lexus crash where the gas pedal was stuck, from the owner putting an all weather floor mat on top of the carpet mat.

islandbeef

I've heard this happen with the older Lexus models.

Check the fuel line to the fuel filter, it (or both) could be clogged.

jkeller

utsandiego.com/news/2009/aug/31/bn31chp-lexus-crash/

bclexus

I assume this is happening with a fully warmed-up engine. If the engine is cold there are a lot of [cold] engine parameters that don't provide for an efficient running engine that performs at peak performance...even at slow speeds and low RPM. If this 'momentary power loss' is happening after the engine has become fully warmed-up it sounds like a random hesitation on acceleration, which doesn't duplicate itself every time...and may not happen but every once in a great while. This, unfortunately, is fairly common with all car manufacturer's drive-by-wire vehicles. The onboard computer (ECU) gets its input parameters a bit scrambled from time-to-time and there is a brief (1~2 second) hesitation before the engine responds to your accelerator command.

If it is happening too often (one time could cause a catastrophe), I'd ask your Lexus dealer's service department to download (overwrite/replace) the latest software for your car's onboard computer. Also, make sure you are using premium grade (high octane) Tier 1 gasoline. And, be cognizant of confusing your car's computer by giving mixed throttle induced signals, e.g. jabbing the throttle for a split second, then no throttle for a split second, then applying throttle again all in a brief one to 3 second time period.

Atomic350F

Perhaps try turning off the TRAC and VSC and lots of experimenting (not in traffic) stamping the pedal briskly as you normally would to determine if the traction control is indeed bogging you down... or if something else is going on.

Hold the traction control button for 3 seconds while the car isnt moving to turn them BOTH off (you should see the TRAC OFF and the yellow VSC icon lit up on the dash). If you find wonderfully crisp instantaneous response with excessive wheel spin maybe that can reflect the issue of too much slippage the ecu is compensating for when vsc is on. If it acts the same and bogs down with all the traction controls turned off, maybe that would mean there is indeed an issue going on with your car.

Try a smooth yet aggressive pedal modulation vs stamping it immediately to the floor also, as once the vehicle is in motion it will find traction much easier, and this would bypass traction controls that may be stopping you momentarily - theoretically.

With the ecu's trying to take over the driving duties as soon as a tire looses any traction nowadays, sometimes less is more - less throttle input would mean less potential wheel spin meaning less traction control bogging you down meaning you actually accelerate sooner.

I wonder if when your in Sport mode if that helps with your throttle response also? This may help pinpoint the cause as ecu related vs something mechanical too.

I would note the traction controls are quite sensitive on this car from my experience during "spirited" driving. However with the controls all turned off the stock tires have a lot less traction than I would have hoped for and things can get loose rather quickly, perhaps reasonably justifying the sensitive traction control settings.

Just a thought here, let us know what you find please.