Mk2 brake lights flashing every few seconds

[JodyS21]

I was following a mk2 today on a 40mph road for several minutes.
When there were no other cars infront (potentially activating its adaptive cruise control), it’s brake lights very briefly flashed on roughly every 5 seconds.

It would've been very interesting if I’d have been able to ask them what setting they were driving with.

It was not slowing down (enough) every few seconds to be caused by the driver pressing the brake pedal repeatedly or I would say by the driver lifting off the accelerator pedal and the KERS causing enough slow down to trigger the brake light.

It really think it must’ve been some automatic system doing it.

The road was pretty flat, so I’m certain it couldn’t have just been normal cruise control that had been set and it had to keep braking to keep the speed under control like it may do on a downhill road (There’s no KERS on cruise control remember it just uses the actual brakes).

All I can think of is it could be something weird to do with using the automatic speed recognition for cruise control - I don’t ever use this myself. Could it be something to do with having the speed limiter set? Or could it be it was on “self drive”???

Anyone come across this before?

 

[DBedford]

Brake lights come on when the car uses regen braking , do they not.

 

[Coulomb]

Brake lights come on when the car uses regen braking , do they not.

Yes, IF the regenerative braking power is high enough. Or at least, that's how it is supposed to work.

 

[Alb]

I think it's most likely the car was just being driven erratically triggering KERS initiation of the brake lights.

 

[JodyS21]

I think it's most likely the car was just being driven erratically triggering KERS initiation of the brake lights.

I don’t think it could’ve been that though, as it was such a regular pattern. Plus it didn’t really slow down at all much every time they flashed, under KERS the brake lights don’t come on unless enough deceleration occurs.

 

[peterseddon]

I you are in KERS 3 and take your foot off the accelerator the brake lights come on.

 

[JodyS21]

I you are in KERS 3 and take your foot off the accelerator the brake lights come on.

The brake lights only come on with KERS once sufficient deceleration is achieved, not instantly.
In this situation, the car was hardly decelerating - if at all; not enough for KERS to trigger the brake light.

Also the brake light was literally only flashing on, every time consistently, which was really weird.

 

[TonyP]

This can happen if you constantly adjust the accelerator position whilst driving....even small adjustments. Have witnessed this whilst following my partner in her ZS EV.

 

[peterseddon]

The brake lights only come on with KERS once sufficient deceleration is achieved, not instantly.

Sorry to disagree, but in my car in KERS 3 if I take my foot completely off the accelerator the brake lights come on instantly.

 

[Alb]

Same in my MG5 hence my original observation.

 

[Striker]

On the ZS MK2 you're foot most definitely does not have to been all the way off the accelerator pedal for the brake light to come on
I've had quite a play with it, it comes on when a certain percentage regen is reached, from memory it's when the gauge is showing -7% (though my memory has been known to fail me )

Whatever the actual figure, the brake light comes on when that amount of regen is reached
Though it equates to a fair amount of braking and pedal movement, I'd have thought it would be unlikely to achieve that on the flat whilst in the flow of traffic, going downhill would be a different story

 

[Verdigris]

Here's my theory. The "flashing" car has the anti-collision system. It has its cruise control set 1 mph faster than the car in front of it, which also has cruise control set, so every five seconds the gap gets too small and the ZS automatically brakes.

 

[JodyS21]

Sorry to disagree, but in my car in KERS 3 if I take my foot completely off the accelerator the brake lights come on instantly.

I get that & agree, lifting completely off (assuming conditions allow max KERS) does cause sufficient instant deceleration to cause the brake lights to come on.

This car wasn’t decelerating hardly anything/ if at all though, so they couldn’t have been lifting completely off the pedal every few seconds to cause the brief flash of its brake lights. This is why it doesn’t make sense what I saw.

 

[JodyS21]

Here's my theory. The "flashing" car has the anti-collision system. It has its cruise control set 1 mph faster than the car in front of it, which also has cruise control set, so every five seconds the gap gets too small and the ZS automatically brakes.

I was thinking along the similar lines.
Although from memory I don’t think there was always another car in front of it…