Blind Spot Monitoring and trailer towing

[howlin4you]

I've been 'borrowing' the CX-5 from the wife this week and had some things to haul around. I used my small utility trailer and noticed the BSM was acting up a bit while driving today. It happened mostly on the drivers side (about 4-5 times) but did happen on the passenger side (maybe twice). I would pass alongside another car and the light would come on like normal when I was next to them, but then it would stay on. A couple times it stayed on for about 30 seconds then went off on it's own, the other times I cycled the switch on and off to clear the light. I asked her if it's ever acted up before and she said no. Has anyone else ever noticed anything like this? Was it the trailer or is my BSM system screwed up and the trailer is just a coincidence?

 

[TreyP]

Probably salt built up on the sensors.

 

[howlin4you]

I just washed it the day before.

 

[TreyP]

It is still winter though, and I see you are in Wisconsin, so it is possible since the sensors are close to the road. One wet spot on the road and the potential is there.
Once the snow started, I also started getting a lot more false positives with the BSM.

Anyway, just a thought, maybe someone has a better explanation.

 

[howlin4you]

I know what you're saying, but I drove it a bit today without the trailer in the same weather on the same roads and it didn't happen once.

 

[Chris_Top_Her]

Are you using the OEM hitch? If you are not, and you have a trailer light harness hooked up would you mind taking a picture? of how it sits when it is in use? Thanks.

 

[phoned]

I'm guessing it's just due to the trailer. Mine picks up static objects behind me sometimes so I can only imagine what pulling a hunk of metal behind you is going to do.

You can turn the BSM off for cases like these.

 

[Simon100]

The UK owners manual suggests turning the blind spot monitor off when towing a trailer. If the trailer is picked up by the monitoring radar it will give a false reading.

 

[howlin4you]

Are you using the OEM hitch? If you are not, and you have a trailer light harness hooked up would you mind taking a picture? of how it sits when it is in use? Thanks.

I'll send you a PM

The UK owners manual suggests turning the blind spot monitor off when towing a trailer. If the trailer is picked up by the monitoring radar it will give a false reading.

As does the US version I just looked at. I didn't think to look there before posting this thread. So it is most likely the trailer, good to know that is probably normal behavior and nothing is wrong. Thanks!

 

[kekek]

My guess would be the trailer. BSM will act up when I have a bike on my rack. Thule T2 upright hitch mount reach. Since the sensors also check behind the car it picks it up.