Recently purchased a 2017 GS 350 (F Sport). Everything has been wonderful for the past ~month or so, including the radar cruise control. However, last weekend I was on a longer drive and the radar cruise control turned off after ~3 hours with the "Radar Cruise Control Not Available" warning and yellow triangle. (It didn't say "clean sensor".)

Weather was clear and HOT, around 100F+. I washed the car since (there were a lot of bugs on the grill) and have tried it again a few times and I'm still getting the error. Is there any way for me to look and see myself what the problem might be (I don't have a diagnostic cable), or do I need to go into a dealer directly to have it looked at?

 

Most Scanners should be able to tell you there is a problem. I would try cutting everything off in the car, then disconnecting the battery for 15mins then reconnect then drive and see what happens. I have also see where it was the Lasers needing realigned, (not sure if this is a Laser one?), some it was just the switch itself gone bad.

 

I'd start off with checking the module and connection itself. You should be able to access it by removing the top access panel (there should be 11 push clips to remove all the front panels).

Make sure connection is solid, leads don't look corroded, etc.



​​​​​​And ditto on the battery disconnect (for a few mins). Have your key in the car and door unlocked (or windows down) when you reconnect. Once reconnected, press the ON button (but don't start the engine) and let everything (start up). Then try starting the car.

 

I had this issue right after buying my car. It was L certified and literally happened to me on the way home from the dealer, so I called them up. They took care of it, said they did the calibration or alignment process on the sensor for the adaptive cruise. Has worked fine since. Not sure how much it would normally cost because it was covered.

 

Same. Mine had to be calibrated. Funny cause I am having this exact issue on Audi now. I wish this wasn't even an option in my cars, useless to me.....only issues.

 

With Lexus you can use regular cruise control even if radar malfunctions. I think you hold the on button. Probably still throws the error message before you go to regular cruise though, if that bothers you. Maybe Audi also has a bypass to old style cruise.

 

I personally hate those things. I would be bored and sleepy following somebody else pace. Also when something goes wrong.

b/c will be along soon to preach a sermon about this problem. That's the end of my Rant.

 

I wanted to quickly follow-up since I super appreciate the instructional advice (and also just in case someone finds this in a google search in the future): The radar cruise control just randomly started working again two days later before I had a chance to open it up and take a look (was planning to do it over the weekend since it wasn't urgent).

The change of functioning was correlated to the temperature dropping from 100+ to the 90 range. I don't necessarily think it was related, but it's maybe an interesting coincidence.

It's going to be 108 this weekend though, so if I'm forced to do any driving, we'll see if it goes out again! I'm guessing since it's intermittent it's probably more likely a loose connection than "it's too hot outside" though.

 

I doubt it's a loose connection. The Lexus connectors have a strong click to them and locked in place. Also the connection is water tight so you wouldn't have any corrosion inside it. Doubtful anything got behind the grill to damage the actual wiring behind the connector.

 

I had problems with the radar cruise several months ago. I ended up spraying WD-40 on a napkin and wiping down the threads of the gas cap. Screwed the gas cap back on and haven’t had the same problem since.

 

That's got to be the randomest "solution" to that problem.

 

If I remember correctly, my bro did a scan and that’s what he suggested. I forget the exact code, etc.

 

I've seen a lot of gas cap related problems and codes before but.... that would be a 1st?

 

Just got my car back.....audi has 2 radars and each one is $3000 plus labor lol

 

Mine just pop up with the same message. Is there away to recalibrate this DIY? Or its take it to Lexus dealer?
I'm going to take the cover off on the weekend to see if there is anything there that needs to be dusted and cleaned like spider webs etc.