2020 GT Right Blind Spot Works 1/3 of time

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Funny that the OP never came back to reply to the thread he/she started.
Anyway, the radar could be defected. This happened to pre-gen CX9 owners.
The new BSM ('17 CX5) is more sensitive than the one on my '16 (Mazda6) or '14 (Mazda3).
i.e. detecting vehicles farer away in adjacent lanes.
 
GaxiBm, i just took owenership of a 2020 cx5 gtr and its doing the same thing passenger mirror bsm is only working about 2/3 of the time. Did you get it fixed? and if so what was the problem ? thank you Dan
Either It has gotten better or I have got more use to it. Compared to my 2013 and 2016 the 2020 has a shorter range and it usually does not detect a vehicle that I am passing in the lane to my right so maybe it thinks I know it is there since I just passed it, maybe it is more intelligent. The local (small) Mazda dealer took a look at it early on and said it was working as described, I ask them to re-calibrate it as I found a procedure in a service manual that described how to do this especially if the rear bumper had been replaced. The service manager wanted to talk to Mazda and I could never get them to call me back so I gave up. It seems to always light up when the vehicle is approaching from the rear and is within a car length of my back bumper right or left (too close in my opinion). I think it is possible that the dealer installed Zurich Shield paint sealer (I did not want but was on the car) may have contributed to the reduction in range and it may now be deteriorating causing the range to improve a bit(?) I did see on several forums where 2019 owners complained the the BSM range was too great and stayed lit up after they passed a car and had sufficient room to merge back in so maybe mazda reduced the range on purpose and programmed it not to detect cars you pass(?) I bought cheap stick on moon spot mirrors and stuck on my rear view mirrors and decided to live with it but I still think it is substandard. Does yours have a paint sealer coating?
 
I think there is some misunderstanding about how the system works. It takes into account your speed, the speed of vehicles in adjacent lanes, and if they are moving towards you or away. If a vehicle is in your blind spot, the light will come on. If a vehicle is gaining on you and will be in your blind spot within 3-5 seconds the light will come on. If you are passing a vehicle, the light turn off once the other vehicle clears your back bumper if it is falling behind you. If you activate the turn signal while a vehicle is in your blind spot or will be in your blind spot, the light will flash and you will get an alert.

I know that the perameters of the system have changed in recent years but I'm not sure how since I only started working for Mazda in 2017
 
I think there is some misunderstanding about how the system works. It takes into account your speed, the speed of vehicles in adjacent lanes, and if they are moving towards you or away. If a vehicle is in your blind spot, the light will come on. If a vehicle is gaining on you and will be in your blind spot within 3-5 seconds the light will come on. If you are passing a vehicle, the light turn off once the other vehicle clears your back bumper if it is falling behind you. If you activate the turn signal while a vehicle is in your blind spot or will be in your blind spot, the light will flash and you will get an alert.

I know that the perameters of the system have changed in recent years but I'm not sure how since I only started working for Mazda in 2017

I think the BSM function was explained some time ago in a different thread, but this is a well-written, spot on explanation. This is exactly how it works in my 2018 CX-9.
 
I think there is some misunderstanding about how the system works. It takes into account your speed, the speed of vehicles in adjacent lanes, and if they are moving towards you or away. If a vehicle is in your blind spot, the light will come on. If a vehicle is gaining on you and will be in your blind spot within 3-5 seconds the light will come on. If you are passing a vehicle, the light turn off once the other vehicle clears your back bumper if it is falling behind you. If you activate the turn signal while a vehicle is in your blind spot or will be in your blind spot, the light will flash and you will get an alert.

I know that the perameters of the system have changed in recent years but I'm not sure how since I only started working for Mazda in 2017
I wonder why the 2020 owners manual says the following because mine does not work like it says:
"The detection area on this system covers the driving lanes on both sides of the vehicle and from the rear part of the front doors to about 50 m (164 ft) behind the vehicle. "
 
I wonder why the 2020 owners manual says the following because mine does not work like it says:
"The detection area on this system covers the driving lanes on both sides of the vehicle and from the rear part of the front doors to about 50 m (164 ft) behind the vehicle. "
In what way is it not working like it says?
 
The detection range is nowhere near 164 ft or about 10 car lengths, I am lucky to get 3 car lengths...
 
The detection range is nowhere near 164 ft or about 10 car lengths, I am lucky to get 3 car lengths...

" If a vehicle is in your blind spot, the light will come on. If a vehicle is gaining on you and will be in your blind spot within 3-5 seconds the light will come on. If you are passing a vehicle, the light turn off once the other vehicle clears your back bumper if it is falling behind you."

My understanding is that the BSM system is always detecting that 50m range, but it only alerts us or notifies us of vehicles in the next lane depending on the scenarios listed above.

In regular traffic with everyone travelling the same speed, the BSM would not trigger if a vehicle was 40m behind you because you have plenty of room to make the lane change. However, if you were on a 2-lane highway in the right lane, and a car in the passing lane is travelling at a faster speed 40m behind you, the BSM would trigger because you would not be able to safely make the lane change at your current speed without forcing the approaching car to slow down.
 
" If a vehicle is in your blind spot, the light will come on. If a vehicle is gaining on you and will be in your blind spot within 3-5 seconds the light will come on. If you are passing a vehicle, the light turn off once the other vehicle clears your back bumper if it is falling behind you."
Where did you quote that from?
 
I wonder why the 2020 owners manual says the following because mine does not work like it says:
"The detection area on this system covers the driving lanes on both sides of the vehicle and from the rear part of the front doors to about 50 m (164 ft) behind the vehicle. "
The detection range is nowhere near 164 ft or about 10 car lengths, I am lucky to get 3 carwhy lengths...
If you keep reading into the Notes following the general explanation in the manual (the 2020 version anyway) there are a whole much of circumstances where the BSM will not alert. Those points might answer some questionable circumstances.

Curiously, one of them is that the radar won't detect or will have difficulty detecting if "A vehicle in an adjacent driving lane is attempting to pass your vehicle." I don't know what that is trying to say since it doesn't make sense on it's face.
 
Where did you quote that from?
That was my quote. And the info is from the Mazda training I received. The sensor is detecting vehicles approx 50m back but it will only alert you if that vehicle will be in your blind spot in the next 3-5 seconds. It would be pretty silly, and annoying, for the alert to go off for every vehicle that came within 50m of you.
 
The detection range is nowhere near 164 ft or about 10 car lengths, I am lucky to get 3 car lengths...
Sensor detection range and sensor alert range are two different things. The alert range is going to depend on what the adjacent vehicles are doing relative to yours
 
That was my quote. And the info is from the Mazda training I received. The sensor is detecting vehicles approx 50m back but it will only alert you if that vehicle will be in your blind spot in the next 3-5 seconds. It would be pretty silly, and annoying, for the alert to go off for every vehicle that came within 50m of you.
I agree that would be silly. One instance where the system won't squawk, according to the manual, is when a vehicle is toward the back of the detection zone traveling at the same speed. The manual does not, however, indicate the kind of sophistication you describe.

I'll check out what you say next time I'm on an expressway.
 
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" If a vehicle is in your blind spot, the light will come on. If a vehicle is g on you and will be in your blind spot within 3-5 seconds the light will come on. If you are passing a vehicle, the light turn off once the other vehicle clears your back bumper if it is falling behind you."

My understanding is that the BSM system is always detecting that 50m range, but it only alerts us or notifies us of vehicles in the next lane depending on the scenarios listed above.

In regular traffic with everyone travelling the same speed, the BSM would not trigger if a vehicle was 40m behind you because you have plenty of room to make the lane change. However, if you were on a 2-lane highway in the right lane, and a car in the passing lane is travelling at a faster speed 40m behind you, the BSM would trigger because you would not be able to safely make the lane change at your current speed without forcing the approaching car to slow down.
Using your light will come on statement, if a car is approaching from the rear say at 80 mph and you are at 50 mph, 30 mph faster than you, that is 13.41 meters per second so if it should alert at 5 seconds away that is 67 meters which is out of the 50 m range so it should alert when it comes in range at 164 feet or 10 car lengths. If it should alert a 3 seconds away that is 40 meters away or 131 feet or 8 car length. Mine does not do that as I get 3 to 4 car length max alert range. Does anyone with a 2020 reading this ever get 8-10 car lengths of alert from a speeding car?
 
Other than the heads up display every car has a perfectly good built in blind spot monitor. Its called adjusting your mirror correctly. - Okay, I couldn't resist. Having it look back along the side of your car only does one thing - let you know if anyone is trying to steal your gas cap. There's those of you that know exactly what I'm talking about and those that have no idea.

Okay, I got my flame suit on
 
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Everyone does realize that audio alerts only works if you use your turn signal, right?
 
Using your light will come on statement, if a car is approaching from the rear say at 80 mph and you are at 50 mph, 30 mph faster than you, that is 13.41 meters per second so if it should alert at 5 seconds away that is 67 meters which is out of the 50 m range so it should alert when it comes in range at 164 feet or 10 car lengths. If it should alert a 3 seconds away that is 40 meters away or 131 feet or 8 car length. Mine does not do that as I get 3 to 4 car length max alert range. Does anyone with a 2020 reading this ever get 8-10 car lengths of alert from a speeding car?

Here's the thing - unless you know the exact speed of the approaching car, you can't really say when the BSM should trigger because it would be based on an approximation. The way I see it, if you switch on your turn signal in front of a car and the BSM does not trigger, you have enough room and enough time to make the lane change while giving the approaching driver time to adjust/react. If the BSM does trigger, its an indicator that you may not have enough time to complete the lane change safely.

My understanding is that the older Mazdas had a more simplified detection system, something along the lines of "if car is XXm behind you, BSM will trigger". The more advanced system is more specific, in that it uses more information to determine whether to trigger the BSM or not.

My suggestion would be to head to the dealer to test drive a different CX-5 and try to recreate the "BSM doesn't work scenarios" with the dealer car. If you can't, you can assume that you BSM system may be faulty and pursue the case further with the dealer. If you can, chalk it up to the new system that operates a little differently.
 
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Around Atlanta interstates if you depend on the light/buzzer only and pull in front of a fast moving car, you are going to get honked at, fingered and maybe shot. Mazda has installed three different BSM systems per the service info and the most recent one is the least desired for my driving. I would like it to always alert if someone is in the alert area and remind me to look and decide if I can safely change lanes. I don't mind false alerts if I am not changing lanes, I just like to know if someone is over there on my HUD in case I have to make a quick move to avoid a problem.
 
Around Atlanta interstates if you depend on the light/buzzer only and pull in front of a fast moving car, you are going to get honked at, fingered and maybe shot
That's everywhere to one degree or another.

One of the more dangerous situations when in proximity to NASCAR wannabes is on 3 lane expressways when, for example, you are in the left lane passing then signaling a move to the middle lane while a transcendatal idot is barreling up in the right lane and then moving to the center lane to pass. The blind spot detector will not flag that guy since it only sees into the adjacent lane and you may not pick him up in a mirror.

Anybody thinking this system or any one like it eliminates having their head on a swivel when changing lane could be in for a deadly mistake.
 
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and you may not pick him up in a mirror.

You certainly should see him approaching fast in the rear view and then as he gets closer the side-mirror. If you don’t, you don’t have your mirrors adjusted properly. You shouldn’t be able to see the side of your car unless you lean back and to the right (right mirror) or smash your head against your driver’s side window (left mirror).

You should always see any car around you. As you pass someone, you’ll see them first in your windshield, than in your side window, than in your side mirror, and then in your rear-view mirror. Each view should overlap slightly (you’ll see the back of the car come into view in in your side mirror while you can still see the back of the same car out of your side windows; and then see it come into your rear-view mirror while still visible in your side mirrors).
 
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