Warning Lights when I brake hard?

[davidmbell]

The Z4 in the UK has a system that flashes all four indicators (orange turn blinkers in UK) if you brake very hard - ie as if you were to slam on the brakes on a motorway.

Any ideas if this can be turned off? I've had it happen twice now while I've been driving 'enthusiastically' and need to disable it.

Thanks

David

[cdeslandes]

Are you sure it's a "system"? Or just your car telling you that something is temporarily wrong?

I experienced a similar thing once in my SAAB 900 Turbo while coming to a stop from 120 mph (don't asK!) Turns out the coolant was sloshing around the expansion tank under heavy breaking and tripped the low-level warning.

This may just be oil or coolant being pushed forward and getting you a false low-level warning...

[davidmbell]

Originally Posted by cdeslandes

Are you sure it's a "system"? Or just your car telling you that something is temporarily wrong?

I experienced a similar thing once in my SAAB 900 Turbo while coming to a stop from 120 mph (don't asK!) Turns out the coolant was sloshing around the expansion tank under heavy breaking and tripped the low-level warning.

This may just be oil or coolant being pushed forward and getting you a false low-level warning...

It may not just be the UK that has this, check the Safety Section on Wiki
http://en.wikipedia.org/wiki/BMW_Z4_%28E89%29#Safety I think this means in the US the actual brake lights themselves blink?

Although in the UK if we brake VERY hard our ORANGE hazard warning lights (indicators/blinkers) come on too. Its quite common for people on motorways to switch on their hazard warning lights if they've had to really slam on and this must be designed to do this for you. But its something I think I should be able to disable.

David

[T89]

Yep this is a safety feature. Depending on the different cars, either the rear fog lights will light up or indicators will flash upon hard braking. It is activated in conjunction with the ABS.

For bmw's, both of these lights will come on, depending on the speed. If you brake really hard but are still traveling at a high speed then just the fog lights will light up. If you brake hard to a full stop or to a low speed then the indicators will come on as well.

As far as I know, all markets have these features. Uncertain about NA. In Europe, we are taught to use our indicators when braking hard on the motorway to warn other drivers behind you.


T

[davidmbell]

But can I turn this feature off?

[cdeslandes]

Originally Posted by davidmbell

It may not just be the UK that has this, check the Safety Section on Wiki
http://en.wikipedia.org/wiki/BMW_Z4_%28E89%29#Safety I think this means in the US the actual brake lights themselves blink?

Although in the UK if we brake VERY hard our ORANGE hazard warning lights (indicators/blinkers) come on too. Its quite common for people on motorways to switch on their hazard warning lights if they've had to really slam on and this must be designed to do this for you. But its something I think I should be able to disable.

David

I guess I misunderstood. I thought you were talking about indicators on the dashboard, but you were talking about the brake/signal lights...
We're separated by a common language!

In that case, yes it's a standard feature. Disabling it would most likely require programming the ECU, not something most common mortals can do.

[T89]

I'm sure it's possible. Just gotta reprogram the ECU.


T

[siscobmw]

I don't know if you can disable a safety feature like that....
Francesco

[rmorin49]

I don't get it, why would you want to deactivate a feature that could prevent someone from rear ending you?

[teagueAMX]

Seems to me it's next to impossible unless you're fluent in whatever code language BMW uses to program their ECU, then you would need the hardware and software capability to hack into the ECU, find the relevant code registers and overwrite them. You would of course need to know the alternate code values to write into those registers, as well; not quite sure where to obtain that info but not likely the public library. Of course the next time you took your Z4 in for a service, they would overwrite your changes with a software update.

But apart from those minor problems, the concept is fascinating. Maybe I don't really understand the issue, but it leaves a big "why" or "what for" in my mind.

1. From inside the car, how do you know whatever it is, is flashing when you brake 'enthusiastically'?

2. What difference does it make? If you're driving 'enthusiastically' as you put it, does it distract other drivers? Attract a constable, etc?

.

[zeez_Dubai]

it happened once to me, was driving around 100 kmph and the signal light went red.
had to break to a standstill.

[Memphis1]

Originally Posted by teagueAMX

Seems to me it's next to impossible unless you're fluent in whatever code language BMW uses to program their ECU, then you would need the hardware and software capability to hack into the ECU, find the relevant code registers and overwrite them. You would of course need to know the alternate code values to write into those registers, as well; not quite sure where to obtain that info but not likely the public library. Of course the next time you took your Z4 in for a service, they would overwrite your changes with a software update.

But apart from those minor problems, the concept is fascinating. Maybe I don't really understand the issue, but it leaves a big "why" or "what for" in my mind.

1. From inside the car, how do you know whatever it is, is flashing when you brake 'enthusiastically'?

2. What difference does it make? If you're driving 'enthusiastically' as you put it, does it distract other drivers? Attract a constable, etc?

.

You'd know because the hazard triangle flashes

And the computer knows if it's a panic brake, it's not about driving fast. So in a track your brake timing is not enough to set them off.

[teagueAMX]

Got it