Yellow triangle master warning light issue
 

On my 2021 ES 350 with 24,700mi I have had at intermittent unexpected times the yellow triangle light flash on for just a moment then off with no buzzing no message and at the same time the throttle goes non responsive and recovers in a second or so. Not a good feeling. Weeks go by and no issue. Mostly happens at above idle and slow take off AC on at all occasions.

I have had the Lexus shop manager test drive and no abnormal drive conditions and reported no codes (DTC's) or internal messages. He said if the triangle stayed on it could be diagnosed - that does not happen at all times with me..

Since the throttle is FBW maybe there is an issue with the throttle sensor position to the computer?

The owners manual states see your Lexus dealer, - BTDT.

Any thoughts on what is going on greatly appreciated

Since there are several separate issues that can trigger that light to come on, it’s going to be impossible for anyone to provide a recommendation with any degree of confidence. I’m assuming you’ve Googled what triggers that light to come on, so I would start there. If it flashes for a quick second and is accompanied by a temporarily dead throttle, I would check to make sure the wiring for the throttle is fastened all the way. If that doesn’t work, maybe try to reset the ECU by disconnecting the battery. Good luck.

If you have a bigger boot, there is a possibility to press both brake pedal and throttle at the same time. In this case, the triangle will appear together with a message “brake and throttle pressed simultaneously” and the throttle by wire will be disabled for half a second.

Thank you that is a great suggestion that I may be inadvertently doing. Will pay more attention and see what happens. I will also do an experiment and do a gentle throttle brake to see if the triangle is activated.

Thank you for the post. I have looked into the reasons for the yellow triangle coming on in Manual and Internet and will check throttle wiring connection. If I disconnect the neg battery cable what issues will need to be corrected for electric items lost how to fix? Will any require a dealer fix?

This happened to me one time while making a u turn with a car in front of me and I had to have my left foot on brake pedal and apparently pushed both at same time and throttle became unresponsive even with no brake pushed. I had to turn car off and back on with cars flying towards me and it put me in a very dangerous situation. There are times in tight situations where foot needs to be on brake pedal if needed. Bet a race car driver would have a heck of a time driving a hybrid.

Not necessarily: I believe all of the Formula 1 cars are hybrids as well as many other series. https://www.speedtechracing.com/the-...rid-race-cars/

Let me rephrase my statement to say Lexus hybrid unless it was designed to keep throttle alive.. Race car driver always keeps left foot on brake. Didn't realize formula 1 was hybrid...thanks for info

You should be able to do it yourself. You’ll just have to redo your presets and other preferences again. You might also have to reprogram the adaptive grid on your backup camera. There is a thread about how to do that. It took me a few tries to get it to work. If you’re not comfortable doing all of this, I wouldn’t do it. I was only suggesting it as a last ditch effort. I would follow the other person’s recommendation about making sure you aren’t accidentally hitting the gas and brake at the same time first.

I did a test on this with not a lot of brake and a some throttle press but no yellow triangle icon. Did this several times and negative. Something else is going on. Maybe throttle sensor has a intermittent signal laps?
Thanks for the suggestion.

Take it to autozone and have them scan the car for free, or you can do it with your own scanner or techstream. While there may not be a permanent DTC, there likely is a pending DTC