Took delivery of our '22 NX350h in November '22. While taking our first road trip in April '23 down to Florida (only 1,800 kms on the clock), I noticed while travelling along the interstate as dusk was upon us, that my driver's side blind spot monitor (BSM) was activating while I was in the left most lane and obviously nothing was actually beside us. At first I thought maybe the steel armco or concrete barriers may be the cause, or maybe road signs. Nope, even as I travelled along with nothing but the grass median beside me it would trigger every once in a while for 5-10 seconds at a time. So I took a few videos of it with my iPhone for a record. It did it again while making our return trip too, so I took more video of it. This has continued to occur and I've continued to take video clips of it, all thru summer of '23. A pattern started to appear, rough paved or old concrete roads were most common. Not potholes but just aged / old roadways that had become very pebbly or coarse, (run flat tires!!) making for a humming / buzzing vibration in the cabin, and at highway speeds, so say 50-80 mph (80-120 kmh). All the while, the system works exactly as it should when an actual vehicle approaches with no problems.

Once I began to have a dialogue face to face with a technician, I explained all the scenarios where it was happening and repeatedly happening on certain roads too. As an FYI to everyone reading, these car's retain a ton of raw data so that technicians can review all of the safety systems operations and providing the exact time down to the second as pulled from my iPhone video's file information helped to confirm if any of these alarms were noted by the computer as being faulty or in error or not. They reported that nowhere did these BSM alarms appear as faulty.

In the middle of all this my driver's mirror assembly was replaced for vibration in January '23, that replacement still vibrated and soon after I noticed the US TSB had come out so we waited until the Canadian TSB was created. Had another complete mirror assembly replaced again when the reinforcement TSB items were installed to correct the vibration. So, when the technician suggested a new mirror at first before looking at the BSM sensor I said "Well that will be mirror # 4 if you want to waist some more time, I don't think its the mirror". My latest visit to dealer in January '24 they reviewed all my videos, took off back plastic bumper and examined the BSM and checked the alignment of it to make sure it was in spec, which it was. So the technician said the only thing left is to replace the BSM. Wait for it...... yes part's on back order! So I'm waiting to see if this problem gets resolved for now.

I've noticed here and there that some owners are mentioning similar driver's side BSM false alarms so I thought I would share my knowledge with you in the hope that you can get your repair done as well.

 

Very detailed explanation. Hopefully the replacement of the sensor will fix your long dragging issue.

 

I have posted this before
https://www.clublexus.com/forums/nx-...t-monitor.html

but you know what the funny thing is? BSM is a sensor in the back of the car in my best knowlege but the issue only happens at night, so I don't know how are they related????!!

 

On my vehicle I was of the same opinion, but once I had an understanding of when it was most likely it was going to alarm (while travelling over rough pavement or concrete at highway speeds) I would keep a very close eye on the mirror and began to 'catch it' lighting up in the daylight too! To help out with this I thought there might be a setting to make it sound yet another annoying beep, but there isn't. You can set the brightness of the light in the mirror though so I made sure it was set to brightest setting to make it a little easier to catch it lighting up.

 

I have a problem with my driver's side blind spot monitor (BSM).
I’m driving a new ‘24 NX350 from December 2023(NJ) and noticed that sporadically BSM from driver side do not work; the passenger side BSM works all the time. I took a video on my iPhone and reported the problem to Lexus dealership, but they said it’s impossible for them to fix it because it not happens all the time. They said that problem may be with a software, and they can’t help me.
I called the Lexus 1-800 and opened a case with them. They said they are going to talk to my dealership, they do not have any record with similar problem being reported, and it’s very hard to prove and fix when it happens sporadically.
When I’m driving and noticing that BSM is not active (and I can see it only on a road with multiple lanes when cars are passing), I can re-set it from the screen with safety assistance (or something like that - I don’t remember the exact name) - I had to turn BSM off, then turn it on, but It stressed me out that I can’t rely on this feature.

 

Sorry to hear you're getting so much push back at your dealer. The proof that it's not working correctly is your video evidence. On an iPhone you can go to the video and locate the little " i " icon that has a circle around it. It's located on bottom right corner on my XR it may be in a different spot on your phone. This provides the date and time and if you select button to adjust the date and time you will see the second you started video as well and you will see at very beginning how long the video is. So you can do the math and determine exactly down to the second when the BSM alarm lit up. You also get a map of your location when it was filmed and if you select the name of the location it will open up maps and give you the pin location with longitude and latitude. I provided all this info for all my occurrences to dealer and explained that it works as it should BUT it also alarms when it shouldn't and the videos prove it. They confirmed within my data in vehicle that it wasn't registering as a faulty alarm and to make certain, they removed the rear bumper and confirmed it was aligned correctly too. Their only option left was to replace the sensor which most likely is faulty internally. Other than that, they said it may be loose electrical connection with the wiring but the BSM is like 99% accurate except my rare occurrences so it doesn't make sense it's wiring.

I'm still awaiting for the sensor to be replaced, so as of now I can't confirm it has solved the problem.

You can prove that the system isn't working correctly because of the video evidence. As for the dealer stating it is the software I would doubt it is a software issue as EVERY car has same software. Plus the dealer should be able to confirm the software isn't a problem somehow to make sure it's all there and no glitches. They all diagnostic computers from Lexus to this exact work! Lexus would know if the software was faulty. Follow up with Lexus customer service in a while and explain your case a little further with them and that the video evidence proves you're having a problem. The dealer is supposed to solve these problems, that's their job. If you have been given some paperwork from your current dealer, and an open customer file with Lexus customer service, take those items to another dealer in your area to continue on with the work. Unfortunately I'm in Canada and my warranty repair work file is not shared with the US network (that the dealer network would see anyways), otherwise I'm pretty sure my warranty claim would be on file in their database.

 

having same issue with my 2024 Nx 350h in the dealership for 2 weeks ordered new sensor should be ready this week fingers crossed also showed video several in fact only driver side

 

I'm having this same issue, still. I also took a video and showed it to my dealer and they said that it was most likely software. Well... I've had my car for over a year now. You'd think it'd be resolved if that's the case.

 

waited 6 weeks for my part got it ban is working properly now Nx 350 h 2024 so far so good

 

This is the standard response from dealers 'never saw or heard of this before'

Let me assure you that they have seen and heard of all the issues that have been posted in the past.

Either they don't know how to fix it or don't want to spend the time troubleshooting it. Mainly the first statement.

They have heard and seen it all. Lexus and the dealer but don't ever tell the customer because they would be required to fix the issue.

 

Actually I had my sensor replaced took 6 weeks to get the part but had the rear sensor left side replaced on my 2024 Nx 350 h works great now 2 weeks in and no issues

 

I was just notified that my replacement sensor finally arrived at my dealer. Scheduled work for May 8 2024, so I'll post once replaced and have some miles on it to confirm it's fixed. Fingers crossed.

aprilkae: As for dealer saying it was a software issue, HA! Software works fine for right side, but has a problem with driver's side. That seems ridiculous. Either software works or it doesn't. I'm surprised they didn't say ' Try rebooting it! '. The software can only interpret the information it's receiving from the sensor. Your video evidence is all you have to prove that the system is faulty. There will be no error codes created in the data. They never found anything in the computer system on my car to indicate it was faulty. Techs said that if it was a wiring issue the computer would probably catch that and throw a code or it could be seen in data.They even pulled off the bumper and checked the alignment. It worked as it should when vehicle approached my car from behind. But video evidence showed it lighting up when nothing was there. That is the only evidence that showed the sensor was faulty.

 

my 2024 NX did exactly the same thing and a BSM module and a recalibration also corrected it. It was back ordered initially and I needed to wait 2 weeks for it to arrive.

 

I have found my people.

Having the same issue on my 2024 NX350. The random BSM lighting up. It happens at all times of the day and all types of locations. I can be driving a two lane road, nothing around me but cows, and it lights up. I had to install a blind spot mirror on my brand new car. Sounds like everyone in here has had success with replacing the sensor. I'll see if I can get that done at the dealer.

Does anyone else have issues with BSM not starting when you remote start your car?

 

My drivers side BSM does not work when I remote start. I have to toggle BSM off and then back on.