Driving up to Princeton today the FLAT TIRE !!! indicator starts flashing and chiming. :'( I just had new Eagle NCT 5 runflats installed a couple of weeks ago. I pulled into the nearest gas station with an air pump and tested all the tires. All normal pressure!! :think: I reset the tire pressure indicator in the system and all has been well the rest of the day.

Anybody else have this glitch??

You could have a really slow puncture or it could just be a false alarm - both are equally likely.

Just check the pressures over the next few days and see if the alarm kicks off.

When I first got my car I had loads of these over a period of a couple of weeks. I actually had a REALLY slow puncture.

Since fixing it I have had one false alarm over a rough stretch of road.

likely a slow flat. i had same and was a nail. got it patched.

Did you reset the system a few weeks ago when the new tires were installed? If not, then what happened today is perfectly explainable. If you did reset the FTM with the new tires, then it could have been a minor glitch and you'll be fine...

Thanks Rudy...I did reset the system at that time. I'll toss the digital gauge in the glove box and monitor the tires closely for that possible slow leak.

As a secondary concern, if I did not have the tire pressure monitor activated, how would I know that I had a flat on a runflat tire? (other than checking the tire pressure) What would stop me from continuing to drive hundreds of miles if on an extended trip? (which I do quite frequently)

Just what are the indications of a flat on a runflat tire?

A primary reason for the FTM system on your car is due to the runflat tires. I don't think it would be wise to install runflats on any car without some sort of real-time pressure monitoring. (I know, the E60's rotational based system could be argued as "not real time" but that's not my point. :P )

You can't detect a flat visually (sure it's possible but it's not likely to be noticed right away) and many people wouldn't be able to "feel" the low tire (even though the car will feel different on a runflat with zero or low pressure).

You can't "deactivate" the FTM so your concern isn't really anything to worry about. If it isn't initialized, you'll likely get false warnings. If it is initialized, you'll be fine.

The biggest thing to worry about is that the tire pressures are all set properly before initializing. Feel free to initialize as often as you see fit, just make sure you do it after verifying your pressures...

I've experienced both types of flats. First time, a slow leak and I also thought I-drive error. Drove from LA to Vegas and back (avg 80-90 mph) and no problems. Second time, I had absolutely zero air pressure (sounded horrible) The tire did the job and got me home.

Here's something interesting: Every time I have a tire replaced, I always get a flat tire I-drive warning (a few hours later). Even after the RFT monitor has been reset. Hopefully not a another slow leak!

If you did not reset the FTM, the fault would be shown for the difference in rotation between the original tires and the replacements.

Indication on a low pressure run flat is low pressure, best detected with an analog gauge,IMO.

Rudy is spot on...if you swap tyres or wheels and dont reset, you will get an alarm, happened to me. Keep an eye out to make sure