Brand new, picked up yesterday 350F and right before driving off the lot, had pre collision malfunction error. Tech drove and reset and we took it home. 75 miles later today and the same pre collision malfunction, with a secondary collision malfunction and parking brake error. Now here back at the dealership and pressed them to not just reset but diagnose. Sucks, 75 miles and it’s my wife’s new whip and her glee quickly turning to disappointment as she’s the kind of paranoid driver for any car problems.

I drove car and it seemed like no other malfunction other than error flashing.

Anyone else have these sensor issues?

 

Service report indicates they found brake actuator stuck, and they adjusted it. Also indicated brake light was on despite brake pedal not being pressed. Makes sense why it could throw the collision sensor error as if brake was being indicated but no pedal. We’ll see. Messages all clear now and will report back if it returns.

Also kinda makes sense why this morning while leaving during dark hours I noticed the brake light to be dim but definitely on. I started it this morning to see if battery drained but it didn’t and started right away. Last night while trying the lock via the door handle touch i waiters for headlights to time out and it did, but didn’t think to check rear lights.

 

UPDATE: Wife drove vehicle about 200 miles last week and same errors returned on a normal drive home this past Saturday. Lexus came to pickup the vehicle and drop off a loaner '17 RX and said they would have a senior tech diagnose the issues on Monday the 24th. He called yesterday and said he did a complete ECU hard reset and wanted to drive the vehicle 30 miles today to see if it returns. His updated report today indicated the error came back at around mile 25. He has ordered a brake actuator and will replace the component.

Anybody experience anything like this on older years? A bit bummed this is on a fresh '20 off the lot.

 

Bummer! I have purchased 2 new RX350 F-Sports, a 2015 and a 2018. Early in my ownership of each, I had questions and observations that I wanted to discuss with the dealer's top technical guy, via e-mail, and he was totally helpful in his explanations of why and how certain things occurred, or didn't occur. On the 2018, the blind spot monitor did not function at all the first day I drove it, and I had an appointment to bring in to the dealer, but then it mysteriously began working as expected, and nothing has failed since. The new "parking" brake function is a little weird, but I have learned to appreciate it. On the 2015, the old school mechanical parking brake actually did not really work -- the car would move if it was put in gear and a little acceleration applied.

I don't like the sound of your problem -- please let us know how it works out.

 

Got back the vehicle on 2/27 and have driven it a total of about 400 miles since. The code and problem has not returned. Hopefully stays that way. The last service report indicated code C13870E. They cleared code and it returns 5 miles after and their troubleshooting led them to replace the brake actuator as it said they found a short.

 

and...same error is back. 🤦🏽‍♂️. Will call service again tomorrow. Reversed out of garage, put into neutral with foot on brake and it came on after about 30 seconds while it was warming up. Drove 3 miles down the street to grab something at the grocery store. Started back up and error still present. Reversed out of parking stall and error went away. Drove back home and pulled into my neighborhood cruising down the streets at about 10mph and it comes back on. Same exact errors as original post.

 

Lemon law threat??

 

Three times strike out for the same problem!!!

 

Well, I never contacted Lexus after the last incident of the flashing errors on 3/21 because since they went out that same day after driving it back home, they haven't came back since. Albeit, my wife has only put like 50 miles on it since then as it's been work from home amid all the current chaos. She last drove it 4/5 and it was fine. However, I noticed last night that the rear brake lamps were on but dim. No other lamps/lights were on. I verified vehicle was locked, and all light switches were in the auto position. Without disturbing anything or starting the car, I had my kid observe the brake lamps as I was just slightly able to pull the brake pedal back with my hand and the lamps went out. I slightly pushed it back in to activate brake and lamps go on full brightness. I release and lamps operate as normal. Perhaps some faulty switch, pedal, etc? I sent an email to the service manager and will wait for a response.
I don't want to go down the path of Lemon Law just yet...maybe one more shot at fixing it. But frustration is building!

 

UPDATE: Got back the vehicle last Friday. Lexus service reports indicated they verified the brake lights were on even when vehicle is off and brake pedal is not pressed. Code C13870E. They replaced the stop light switch. Have yet to drive vehicle a good amount of miles due to quarantine orders but will report back if errors reappear.

 

If this happens again, I'd start browsing the dealers lot to see what else he's got that catches your eye.

 

The brake light stuck switch is very common in all makes.

 

annnnd....the same errors are back after roughly 50 miles.

 

Demand they take this RX back and give you a new one. That sucks! Or Lemon Law it.

 

That's completely unnacceptable. You need to start having hard discussions with the dealer about a replacement. If they don't agree, you should consider an attorney to send a strongly worded letter. If that doesn't work, lemon law it.

You have a lemon by most definitions. You paid a ton of money for a brand new car. Heck, not even a used car has that many problems.

Best of luck.