Red Run Flat Indicator

[Mark-Z4]

Driving this morning on the motorway my run flat indicator came on, the red light. I pulled over and checked tyres, no flats (i dont have run flats) and car felt fine.

I did notice a brake smell and a little smoke coming off rear OS caliper, i initially thought it was a pad sensor as they are close to replacement. But i think this is a different indicator?

Ive reset it at work and the light has gone out but ill have to see if it comes back on.

Any ideas? Thought maybe something got stuck in the caliper, stone etc?

 

[Ducklakeview]

Did you actually check the pressures? A runflat will still look pretty much the same with ZERO air in it.. Sticking pads/caliper shouldn't trip it, as the system compares the relative rotational speeds of all four tyres and if it detects one turning faster, indicating a loss of pressure, it flags up the red light. If a caliper was dragging, it would, if anything cause a wheel to turn slower.

Mike

 

[Crazy Harry]

What were the weather conditions? - daft question I know but I've had the same indication going through surface water on the motorway at speed. Slight loss of contact on one corner; car senses that one wheel is rotating faster than the other and deduces a puncture.

 

[G600]

Recently swapped the wheels round or changed tyre pressures? That can trigger it.

 

[weegeoff]

Recently swapped the wheels round or changed tyre pressures? That can trigger it.

Have you tried swapping the wheels round. :? :? :?

 

[G600]

Recently swapped the wheels round or changed tyre pressures? That can trigger it.

Have you tried swapping the wheels round. :? :? :?

Huh?

 

[Mark-Z4]

I dont have run flats so a flat tyre would be obvious i think.

I checked tyre pressures on Sunday, all were ok and ive driven car since. Wheels were off 2 weeks ago to paint my calipers.

Weather conditions were damp, but not raining. Im going to check car over before i leave work, then its 30 miles home.

What im wondering is if the caliper is stuck open, which would set off the indicator i guess when braking?

Thanks for the replys.

 

[PinkPineapple44]

As Duck said, have you actually tested the pressures with a gauge? My E89 likes to flag up a pressure deviation from about a 10% and up range along the same axle; i.e 34psi on the FR and 30psi on the FL would spark the check pressure light to come on. The code on the dash (of my E89 anyway) also tells me which tyre is the suspected low baller

 

[ekimj10]

Have you tried to reset? very often works for me, any change to the wheels seems to tyrigger iy off, such as putting your winter wheels, guaranteed to cause a red light.

 

[Mark-Z4]

Checked pressures after work, they are as i set them on sunday.

I reset the indicator and drove home and thr car was fine. Pulled over to feel temp of calipers and they were cool so guess there's no binding. Maybe something like grit got into the caliper.

Im doing the same drive tomorrow.

 

[mjennings23]

I’ve had mine trigger before, all tyres fine so I reset it and it didn’t come back in 4 months. Pretty sure if there was an issue I might have noticed it in that time!

I anticipate the sensors are quite cautious and trigger on any presumed irregularities as a precaution to get you to check physically

 

[weegeoff]



weegeoff wrote: ↑
Wed Oct 18, 2017 2:59 pm

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G600 wrote: ↑
Wed Oct 18, 2017 2:38 pm
Recently swapped the wheels round or changed tyre pressures? That can trigger it.
Have you tried swapping the wheels round. :? :? :?
Huh?
My wheels are sided and different front and back try swapping them round

 

[Mark-Z4]

Well I do have some kind of issue developing. Tonight on my drive home, the car felt strange at low speed, like something was rubbing, then I started to realise it felt like a warped disc.

The same caliper I had issues with was red hot. So I'll have to get it booked in for further investigation, I knew the discs and pads were low and I've bought new in advance but looks like I have a caliper/hub problem.

 

[weegeoff]

I think you have a seized piston in your calliper. You can do this yourself. It might be a bit fiddly the first time but it comes easy with practise. You can buy the kits, and somewhere on the forum it tells you how to fit them. It will save you £££££zsss

 

[Mark-Z4]

I think you have a seized piston in your calliper. You can do this yourself. It might be a bit fiddly the first time but it comes easy with practise. You can buy the kits, and somewhere on the forum it tells you how to fit them. It will save you £££££zsss

You would be right
The initial light coming on was the caliper seizing, then the next few weeks it got progressively worse.
I needed new discs and pads anyway so fitted a new caliper (£83) and did those at the same time. It's surprising the difference the fault made to the car, prob because it was gradual I didn't notice so much.

 

[greg1953]

I've just had the red tyre pressure indicator come on, pressures are fine, it won't re set , brakes appear ok and tyres have been on for over a year, not run flats,...any ideas anyone ???
Greg

 

[Mark-Z4]

I've just had the red tyre pressure indicator come on, pressures are fine, it won't re set , brakes appear ok and tyres have been on for over a year, not run flats,...any ideas anyone ???
Greg

Sounds like a sensor fault, not sure you can find out which one unless plugged into a diagnostic.

 

[weegeoff]

Take every wheel off and look to see if you have a nail in one of your tyre's. They can be hard to spot when they are still on the car. and will hold the pressure for a while.

 

[cj10jeeper]

I think you'll find a dragging caliper could cause the light to trigger as the system measures the rotational speed difference between wheels using the ABS sensors on an axle. It ignores short time differences, else every corner or wheel slip would trigger it.
Your dragging caliper will make that wheel slower. by a small %, just as a slightly low tyre would increase it by a small %

Hope you fix the brake issue and all is well