I’m calling on the collective wisdom of this forum as I don’t remember this behaviour before, and the main dealer cannot find a problem, although they’ve only read the codes (no errors logged) and done a "hard reset".

The "problem" I’m experiencing is I get no Near Side Blind Spot Warning when overtaking vehicles when the speed difference between the two is equal to or in excess of 10mph e.g. lorry driving at 56mph, I overtake at 66 or greater, I get no blind spot warning.

It’s the same irrespective of vehicle type or size, it always seems to be the speed difference. The Offside warning appears to work as expected, overtaking in France worked irrespective of speed difference.

It’s just the near side that doesn’t appear to me to be performing as the offside does.

The question I have is; is this normal/expected behaviour and I’ve just not noticed it before?

Many thanks
John

BSM is meant to warn of vehicles approaching/overtaking you, so not you passing them. I've noticed the same effect as you (but without checking the speed difference) and think it normal. Only Range Rovers since 1988

CS - Thanks for the reply I like the logic in your explanation.
I’m certainly leaning towards "normal" instead a "weird".

I though Blind Spot Monitor was exactly that they illuminate whenever there is a vehicle in your blind spot regardless. I think they illuminate solid for BSM. Maybe they cannot react fast enough at a high speed overtake? I want to say mine work all the time except at low speed but couldn’t say for sure.

Closing Vehicle Sensing is where they flash rapidly when someone is coming up on you fast from behind.

You also have Reverse Traffic Detection that is for when your backing out a spot and a cars coming from either side.

I’ll have to do some overtaking later 🤣 but to me BSM is to help stop you pulling in on someone that’s in your blind spot so applicable to overtaking? Sold - Bell a 2015 MY16 Loire Blue Autobiography 4.4 SDV8
Previously George a 2007 MY07 Java Black VSE 3.6 TDV8
Previously a 04 MY04 Defender 90

TJH1985 - Thanks for the reply and the thought of experimenting. As we have the same vehicle (even down to the colour!), it’d be a worthwhile comparison.

TJH1985 you are quite right it does come on when one is passing someone, so one does not cut in on them, but as millerj90 says it does not seem to come on when one passes more quickly (I've noticed it mainly with HGVs). Only Range Rovers since 1988

millerj90 wrote:

TJH1985 - Thanks for the reply and the thought of experimenting. As we have the same vehicle (even down to the colour!), it’d be a worthwhile comparison.

Sounds like a fine choice of car

I think you and CS are probably correct, maybe its too brief a moment to trigger them at speed  Sold - Bell a 2015 MY16 Loire Blue Autobiography 4.4 SDV8
Previously George a 2007 MY07 Java Black VSE 3.6 TDV8
Previously a 04 MY04 Defender 90

Just as some closure to this. I took the local dealerships Workshop Manager for a drive today to demonstrate the fact that BSM doesn’t always "spot" vehicles.

During the drive he informed me that the system is more complicated than just a radar. It is taking speed inputs; and if you’re travelling fast, it calculates that you’ll be a long way past the near side vehicle if/when you decide to pull in.

You can demonstrate this to yourself by overtaking a vehicle (at speed), when the BSM would not indicate the vehicle. If you then remove your foot from the accelerator, the BSM indicates the conflict and warns you of it.

It actually makes some sense to me, and now I understand that, I’ll find something else on the car to worry about.

Id agree that both of my 405's have lived up to your findings sir