Red Run Flat Warning lamp came on this morning

[DrunkenNinja]

I was driving to work this morning and the run flat indicator light came on the dash, I checked the tyres and all seemed fine, but reading the manual it states that this light only comes on when a substatial amount of pressure is lost from one of the tyres...

I recently changed my tyres and now have nitogen gas in them so I have a theory that I needed to reset the system to accomodate this change. upon holding down the run flat button for a couple of seconds the warning light turned from red to yellow and then disappeared...

It's strange though cause I have been driving on the new tyres for a few days...

Is my theory correct? or will I have a problem?

[X5 Meister]

I didn't know the light changed colors. It is recommended that you check tire pressure regularly, does that mean you need to go to a special place and get a boost of nitrogen every time?

[DrunkenNinja]

I think yellow is the test colour and red the problem colour... In the U.S. manual this button does not seem to exist...

It seems that once you have nitrogen gas you can only top up with nitrogen you can't mix with air... Normally I would check the pressure at the gas station but since they only have air, It might accidently pump some air into the tyre...

The tyre shop asked me if I wanted the nitrogen for free since I bought 4 new tyres and thought initially I would have been silly to refuse, but with top ups at 3 euros I'm thinking it's probably a good money spinner for them...

Apparently the Nitrogen is better in hot climates as it keeps the tyre cool and apparently makes the ride smoother, I can't complain the tyres feel great, but I think I should have reset the Run flat system after they were fitted...

[killcrap]

an error in the EHC2 control unit sometimes causes the tpm light to come on at times, and same with the LWS. If the light comes on again have the fault memory interrogated and perform any relavent test plans.

[motordavid]

I would think Killcrap's answer is the key; I doubt that the TPMS can distinguish between a ~99% nitrogen fill,
and the ~78% nitrogen mix found in "regular air". ;>)
GL, mD

[DrunkenNinja]

I'll test it on the way home and see if it lights up again, I'm pretty sure it's these new tyres though, one way or another...

Hopefully the reset done this morning is the end of this story...

[DrunkenNinja]

No problems since doing the reset, I did notice this moring though that inside the door where the tire pressures are located there is a HUGE Run Flat Icon with the words Reset blasted underneath it...

Funny how they could not put this info in the owners manual, but at least I know it's definately fixed...