2014 Mazda CX-5 BSM Issues

I currently dont have the car as its still at the dealership, but from the manual found on Mazdas website Although the system may detect objects on the road side such as parked vehicles or guardrails and operate the warning light/beep, it does not indicate a malfunction. The funny thing is, Ive passed plenty of broken down cars alongside the highway and it never went off for them. Im just wondering if my issue is completely normal? Is the sensor the only thing that could be causing it? I really wish Mazda would step up to the plate.
 
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nick, have you considered buying a sensor and replacing it yourself?
 
BSM should be a small range detector since it only detects the next lane. For me it never does what you described. RCTA is more sensitive and warns about cars on the road when I am backing in a corner lot. So BSM detecting anything more than 10 feet away seems abnormal. It is also surprising you got an old 14 as CPO.
 
Kaps said:
BSM should be a small range detector since it only detects the next lane. For me it never does what you described. RCTA is more sensitive and warns about cars on the road when I am backing in a corner lot. So BSM detecting anything more than 10 feet away seems abnormal. It is also surprising you got an old 14 as CPO.
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I wonder if somehow mazda doesnt have the cpo record, and therefore they always considered it an out of warranty claim
 
shadonoz said:
nick, have you considered buying a sensor and replacing it yourself?
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Im at the point, I just wanted to make sure it wasnt normal before spending the money and having the same issue. I really want to avoid the Mazda dealerships and just have an independent install it. I was thinking about getting a used one as Im already taking a gamble. I feel like it should be at this point, I dont understand why Mazda wont budge.
 
Originally in August they did not have it on file, and I had to contact the dealership where I had purchased the car. It has been updated since then.
 
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Kaps said:
BSM should be a small range detector since it only detects the next lane. For me it never does what you described. RCTA is more sensitive and warns about cars on the road when I am backing in a corner lot. So BSM detecting anything more than 10 feet away seems abnormal. It is also surprising you got an old 14 as CPO.
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I bought the car in 2017 as a 3 year old off lease car. You can go buy a 2013 CPO Mazda with 70k on the clock today. I dont consider my car that old tbh.
 
If it bothers you that much put a bit of gaffer tape over it. It doesnt look right but its hardly even an irritation let alone stressful and worth going to war with Mazda.
 
Kaps said:
BSM should be a small range detector since it only detects the next lane. For me it never does what you described. RCTA is more sensitive and warns about cars on the road when I am backing in a corner lot. So BSM detecting anything more than 10 feet away seems abnormal. It is also surprising you got an old 14 as CPO.
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BSM and RCTA both use the same radar sensors at rear corners.
 
nicknick9109 said:
I bought the car in 2017 as a 3 year old off lease car. You can go buy a 2013 CPO Mazda with 70k on the clock today. I dont consider my car that old tbh.
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Based on an old thread apparently Mazda had revised the BSM radar sensors on 2014 CX-5 so that if you have one damaged, you have to replace both sides with revised sensors. I wonder the original sensors may have some issues hence now you're experiencing if.

And yes replacement radar sensors require calibration with expensive Mazda equipment hence I believe only Mazda dealer can handle this job.

Replacing The Blind Spot Monitoring Radars

Since you already have lawyer involved, find out how much would it cost replacing both BSM radar sensors and see if it worth it to file a small claims court lawsuit if MNAO is still not willing to do anything after you told them so.
 
yrwei52 said:
BSM and RCTA both use the same radar sensors at rear corners.
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While that is true the RCTA is more sensitive. Try backing up in a corner lot with two roads. It detects the cars even if there is landscaping in between. On BSM if I move a lane it only checks for next lane and not beyond. I have never felt that stranded cars walls etc get detected.
 
Wonder if he might be getting crosstalk somehow between the RCTA and BSM. The descriptions suggests that he's getting BSM alerts from the RCTA.
 
nicknick9109 said:
Heritage07, have you ever attempted to have it looked at? Do you find it to be a nuisance? I’ve had other CX-5’s as loaners and they did not have the same issue nor other Mazda models. I’ve talked to many different CX-5 owners who also claim to never have the issue I am facing, including repersentives at Mazda themselves! Is it possible that both of our cars have the same issue?
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I never had it looked at because as silly as this my sound I don’t pass many guardrails that are on my passenger side. I keep the volume on the lowest setting as well.
 
yrwei52 said:
Based on an old thread apparently Mazda had revised the BSM radar sensors on 2014 CX-5 so that if you have one damaged, you have to replace both sides with revised sensors. I wonder the original sensors may have some issues hence now you're experiencing if.

And yes replacement radar sensors require calibration with expensive Mazda equipment hence I believe only Mazda dealer can handle this job.

Replacing The Blind Spot Monitoring Radars

Since you already have lawyer involved, find out how much would it cost replacing both BSM radar sensors and see if it worth it to file a small claims court lawsuit if MNAO is still not willing to do anything after you told them so.
Click to expand...

I had in the past asked dealerships about calibration, and they all said there is no way to calibrate them. I found online that there most certainly is a tool labeled under the Mazda Special Service Tools category. I initially asked for just the sensor to be calibrated when this issue first started and every dealer including Mazda has claimed over and over there is no calibrations that can be done. I had called the dealership where the car currently is to ask about replacing the sensor, they told me just the passenger sensor would need replaced since I complained thats the side with the concern. They quoted me $780.32 installed. They said its about an hour of labor. I asked if that includes the calibration, they told me it doesnt get calibrated and that its a plug and play module so to speak under the bumper. I do know that a Mazda dealer has previously taken the bumper off to verify the part number with Mazdas tech support hotline.

My question is, could it be my sensor just needs calibrated that I have now? Why wont anyone admit that such a tool exists? I even found the part numbers for two different calibration tools online! They act like Im crazy. I no longer have an attorney involved, I had initially tried to go on the magnuson moss warranty act from a lemon law attorney.

It makes sense that both sensors would need replaced, and I just cant understand why everyone at the dealerships and Mazda themselves are acting like a calibration tool doesnt exist. Its all so frustrating. Is there any Mazda techs on here that could verify that said tool does indeed exist?
 
The tool isn’t for recalibration the radar sensors, they should plug and play but if you change the right side you must change the left side. You can change the left side on its own.

There is a plug in special tool to recalibrate the BSM control module but that is not for the fault you describe, it’s for when the BSM OFF light illuminates because the radar units believe that the bumper is too dirty to operate properly. That tool is part no MD16_BSM_KE. It’s the risk of googling your fault, you can get the wrong end of the stick.
 
nicknick9109 said:
I had in the past asked dealerships about calibration, and they all said there is no way to calibrate them. I found online that there most certainly is a tool labeled under the “Mazda Special Service Tools” category. I initially asked for just the sensor to be calibrated when this issue first started and every dealer including Mazda has claimed over and over there is no calibrations that can be done. I had called the dealership where the car currently is to ask about replacing the sensor, they told me just the passenger sensor would need replaced since I complained that’s the side with the concern. They quoted me $780.32 installed. They said it’s about an hour of labor. I asked if that includes the calibration, they told me it doesn’t get calibrated and that it’s a plug and play module so to speak under the bumper. I do know that a Mazda dealer has previously taken the bumper off to verify the part number with Mazda’s tech support hotline.

My question is, could it be my sensor just needs calibrated that I have now? Why won’t anyone admit that such a tool exists? I even found the part numbers for two different calibration tools online! They act like I’m crazy. I no longer have an attorney involved, I had initially tried to go on the magnuson moss warranty act from a lemon law attorney.

It makes sense that both sensors would need replaced, and I just can’t understand why everyone at the dealerships and Mazda themselves are acting like a calibration tool doesn’t exist. It’s all so frustrating. Is there any Mazda techs on here that could verify that said tool does indeed exist?
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Actually I was surprised MNAO didn't do anything for your BSM when you still have CPO warranty. At least they should ask Mazda dealer hooking up M-MDS computer and checking if there's any DTCs stored in the BSM control modules (radar sensors) on both sides. According to Mazda Factory Service Manual, whenever the BSM control module is replaced, a BSM radar test needs to be performed.

Mazda Factory Service Manual said:
CAUTION:
If the BSM control module is replaced, not performing the BSM radar test will cause a deviation in the radar emission angle which could result in the system not detecting a vehicle approaching from the rear correctly. If the BSM control module is replaced, perform the BSM radar test.
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Whenever anyone replaces one BSMCM, if the part number on replacement one is different from your original BSMCM, you had better replace both sides with the latest revision number and perform the BSM radar test.

attachment.php

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BSM Control Module Removal_01.jpgBSM Control Module Removal_02.jpgBSM Control Module Removal_03.jpg
 
I wasnt aware that there was a test that could be performed. I was told they physically inspected the condition of the module units themselves and drove the car. They never once mentioned any kind of radar test. Im curious as to what it involves if anyone knows? Is it a special tool or something?
 
If it is only a problem at night you may have a short circuit in the plug in from the door to the car (from the light on the outside mirror to the blind spot circuit). It is documented on here that on the drivers door water can get trapped in the door plug and cause unusual electrical problems. I would get both doors unplugged and checked for water inside the plug causing this unusual problem.
 
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