Recently purchased a RX with 12 inch screen (not sure if that matters with what I am trying to describe) that has the BSM and RCTA. I know you can control the sensitivity of the sensors, but have any of you experienced the following? When passing a car that is on the right hand side at a far greater speed than the other car is traveling, the right side mirror's BSM never turns on even as the other car passes through my blind spot. If the car on the right is approaching me (or if I pass them) at a much closer, relative speed between us, the right mirror's BSM does indeed turn on. This has me puzzled...Is the BSM speed sensitive, or I'm missing a setting somewhere.

Also with the RCTA, sometimes the display on the screen does not turn on to show which direction the approaching car is coming from. Both of the side mirror's blink and the audible tone is always heard, but the display on the screen doesn't always flip on to show the direction of the approaching car. Have other experience this as well? I'm wondering if the RCTA is also speed sensitive. If the approaching car is going fast, the screen doesn't have time to flip, if the approaching car is going slower, the screen does show the direction of the approaching car.

Thoughts if this is normal behavior or a problem?

Thanks!

 

BSM stands for Blind Spot Monitoring. If you can see the car then it is not in your blind spot. I would think it is common sense to know if you pass a car that it is now on your side.

The cross traffic alert is designed to alert the driver of an approaching vehicle while they are backing up. At this point the driver can turn around and look where it's coming from before moving back.

Both of these use sensors under the rear bumper on the rear corners to detect vehicles that are not easily visible to the driver and alert the driver.


Unfortunately the driver still has to be engaged and alert. Auto pilot is not here, yet. Soon!

 

I'm not arguing your obvious common sense comment. Yes, the driver always needs to be aware and actively engaged. I'm asking if the behavior of the system is as expected or if it's not functioning properly.

 

This is not entirely true. Lexus BSM is supposed to detect cars that are approaching rapidly from either side, even when they are visible in your side mirrors. So it will detect cars that are not just in your blind spot! I read this in the manual a few nights ago.

 

[QUOTE=lexitaxi;9553488]Recently purchased a RX with 12 inch screen (not sure if that matters with what I am trying to describe) that has the BSM and RCTA. I know you can control the sensitivity of the sensors, but have any of you experienced the following? When passing a car that is on the right hand side at a far greater speed than the other car is traveling, the right side mirror's BSM never turns on even as the other car passes through my blind spot. If the car on the right is approaching me (or if I pass them) at a much closer, relative speed between us, the right mirror's BSM does indeed turn on. This has me puzzled...Is the BSM speed sensitive, or I'm missing a setting somewhere.

Also with the RCTA, sometimes the display on the screen does not turn on to show which direction the approaching car is coming from. Both of the side mirror's blink and the audible tone is always heard, but the display on the screen doesn't always flip on to show the direction of the approaching car. Have other experience this as well? I'm wondering if the RCTA is also speed sensitive. If the approaching car is going fast, the screen doesn't have time to flip, if the approaching car is going slower, the screen does show the direction of the approaching car.

Thoughts if this is normal behavior or a problem?

Thanks![/QUO

You are correct in the sense that the blind spot monitor is not active while passing cars. eg. passing stationary cars on the side of the road the BSM will not constantly flash at you. Would simply not make sense for the car to give you an alert of the car you just passed by. As far as the RCTA is concerned I have noticed that if I am merely crawling backwards I am not given an alert of a pedestrian walking behind me VS a car coming from the right side.

 

It's monitoring beside and behind the car only. Not sure how far behind though.

 

I adjusted the sensitivy to ONLY blind spot.

DIdn't like how it was laggy after the car left the blind spot. Now when the car passes the blind spot, it turns off.

 

From what I've read the RCTA system is indeed speed sensitive. For example, the owners manual notes that if a cross traversing vehicle is coming "Fast" at 18 mph then detection distance is up to 65 feet away. Whereas if the cross traversing vehicle is coming "Slow" at 5 mph then the detection distance falls to 18 feet. So even though the oncoming car is approaching "Fast" the detection range is greater and your screen should flip and show the direction, one would think.

 

"Approximately 9.8 ft. (3 m) to 197 ft. (60 m) from the rear bumper" per the manual. It looks very far behind your car and not just in the blind spot.

 

I'm finding a similar issue to what you are describing Lexitaxi.
I find my left sided BSM works perfectly fine, but my right sided BSM seems to miss about 5-10% of cars that I know are in my blindspot.
I notice your issue of cars that seem to zip quickly by the right side seem to fail to alert the BSM (but the left side is ok).
I also find the right sided BSM seems to miss tractor-trailers, taller cars, and white cars at a higher rate.

It's not confidence inspiring, but I intend to mention it to dealer and the next service and see what they might suggest. It almost seems to me the angle of the right BSM radar might be a bit off, or perhaps the reach of the radar isn't as strong as the left side.

 

I also see a similar issue. Reading the manual it states:
"Conditions under which the BSM function may not function correctly:
When there is a significant difference in speed between your vehicle and the vehicle that enters the detection area.
When the difference in speed between your vehicle and an other vehiclei s changing."

I also thought it might be a "feature" so it won't activate when passing parked cars.

 

if you see a car on either side in front of you and the you're passing with faster speed, it will not alert you but ler you use common sense and look at the mirror if you decide to cut in front of that vehicle.
And yes, it's speed sensitive! At the same distance, if other car travel faster than your car, it will alert you. If your car travel faster, it won't alert you! This is also common sense!
Just like another post, auto pilot is not there yet!

 

I guess my primary issue is, I find my left side BSM works perfectly fine as I expect it to work, but my right side BSM seems to have quite a number of false negatives.

If the BSM on both sides were equally as 'bad', I'd would simply chalk it up to the technology needing more time to mature.

However, given that I find the left sided BSM is superior compare to the right sided BSM, that suggests to me something is going on with the right sided BSM.

Also, I tried the setting of BSM set to early detection, assuming that makes the sensors work at maximum capacity (or at least the algorithms set to minimize false negatives at the expense of higher false positives), but that has not equalized the abilities of the left vs. right BSM.

 

Did you adjust the setting in the menu? You can adjust the sensitivity.

 

Same my right side seems to miss alot of cars too!