ads500

Hi,

Firstly, I am a newbie to the world of BMW. I have recently purchased my 04 e61 525i, i have had a couple of problems with the car to date. One being a replacement of the rear suspension pump, i was getting the system level control faults.... garage diagnosed it as faulty pump. It was replaced under warranty thankfully other wise i would not have been a happy bunny for sure!!

Secondly i had the oil level sensor short circuit the engine injector electrics which left me stranded as the engine would turn over but not start. So after a new oil level sensor and 300 hundred smackers later, again on the warranty. I was back up and running.

Though the main reason for this post is to enquire about the RPA tyre pressure system. Last week drive told me i had a puncher (not the first time i have had the warning), so i pulled over checked the tyres with no obvious flat visible. So i preceded to the nearest garage, checked the tyre pressures on all wheels and set to recommended pressure, reset the RPA in idrive and i was of on my way again. On the way to work this morning i get another puncher warning, so i go through the procedure just mentioned, this time the tyres have no difference in pressure and are spot on from last weeks check.

I am aware the RPA system is a sensitive sole and was wondering whether a difference in tread depth across an axle would be enough to affect the rotation calculation and set a warning off. I have a NSF tyre that has a good 4mm tread before the legal depth markers, and then the OSF tyre is maybe 1-1.5mm from the legal depth marker. i am maximising its life out, as the run flats are so expensive. So in theory as the circumference of the tyres are different, over a hundred miles or so this may affect the rotation speed/count and flag a warning.

I was wondering if anyone may have more experience than me in a scenario such as this.

Any help/advice would be greatly appreciated.

adam

foxhotel

Jepp, been there done that.
I have problems with this around this time every year, it seems to me that its sensetive to in and out of tunnels, maybee temprature related?
If there are uneven round, not sure of the word, but the road is more worn out where the tyres are and when i drive at road that is not that good, its comes up, but strangely enough mostly around these times.
I have changed from rft to regulary tyres and that helped a little.

Not the answear you where looking for, but hey, :-)

JasonH

On a 2004 car the RPA warning is probably over sensitive (and can be a pain). On later years they changed the title to Flat Tyre Monitor (or something similar) and reduced the sensitivity. With the reduced sensitivity I'd already noticed the puncture and was pulling over before it gave me the warning...

Just reset yours (again) and hopefully it will set itself up with a reasonable benchmark and stop giving you the warnings.

fletchedpair

Hi ads500,

I get this warning during this time of the year only, I think it has something to do with change in tempreture or humidity as the RPA it quiet during the summer months even when driving on our horrible UK roads and loaded up with passengers and a roofbox. I did the same as you when I first got the message but I have owned my E61 for a few years now and know it is a trait of the year/model.

ads500

Thanks for the reply's, i guess ill just have to accept it as an over sensitive system and reset it when it flags awarding message.

Lotus99

Yes, with big temp changes, the tire pressure drops, and so it might see it as a flat and warn you. That's why you need to add air as temps drop in the winter to keep the recommended pressure. Whenever you check and fill your tires, you should reset the system so it memorizes the new values.