I had a tire replaced on the rear of the mini today since there was a screw in the edge of the original one. It was replaced with an identical Dunlop SP9000 Sport in 205/45 R17 runflat. The rears were originally on the front so they were the most worn. Would the difference in the brand new tire and the worn one make the warning light go off again since the system operates on the circumference of each tire? The light cleared, then came back on about 20 miles later. I'm thinking I may have to switch one front with the new rear to "match" them a little better and keep the light off. Any input?

 

I would check the pressure in all four tires, perform the TPM reset procedure in the owner's manual one more time, and go from there. No need to start swapping tires around until you're sure it's going to keep giving you the warning light.

 

My original post was starting to get a little long so I omitted saying that I had done that. My bad. But yeah, I usually try to eliminate all the simple things before I start "working" on stuff. I'm going to check them all again in the morning and make sure I didn't pick up something in another tire. Lord knows it's possible. Thanks for the input Scott

 

Get non-runflats.

 

I don't think that will help him out with his TPMS issue (unless the problem is the tread-depth difference between his new tire and his old ones, in which case I guess getting four new tires (run-flat or not) would help.)

 

Me, myself, would do it in a heartbeat. But it's really the wifes new broom. lol She didn't like the idea of not having runflats and no spare. I priced the Kumho runflats and may end up going to them. They seem to have real good ratings compared to the Dunlops. Or I might just get another Dunlop and put both the new ones on the front. IDUNNO...

 

As I understand how the system works, once you have reset it, as long as the tires don't change air pressure, circumference, then it should not give a warning. In other words, it does not care if the right front has x amount of pressure and the left rear has y amount of pressure, all it worries about is that each tire stays the same.

Mark

 

Ok. I figured it out. Checked all pressures. Good. Re-initialized the runflat system. Still had trouble. Finally figured out that if the car rolls ANY between starting it and setting the light then it won't initialize. I was on the driveway and always take the brake off right after starting. It rolls just a little but enough to screw with setting the system. I got on the road, turned the car off and waited a sec. Restarted the car, left the brake on, hit the initialize switch until the light came on, THEN drove down the road. It reset just like it's supposed to.

 

If you have to be still when reseting the system, how can that work? By that logic if I have a leak and I reset the system, it won't go off again unless the tire leaks more.

 

Thats not my understanding of how the system works. It compares the number of times each tire rotates during a fixed interval, and if there is variation among the 4 tires that exceeds some percentage (that I don't know) it triggers the warning light. Your description would suggest that you could mount 4 widely disparate tire/wheel assemblies, reset the TPMS, and as long as each tire continued to maintain its pressure, and therefore continued to rotate at its own speed, the light would never come on. I don't think so. Anyone?

 

According to the owners manual (oh no a guy reading directions) any time you take a wheel off the car for any reason you should reset the tire monitor. I have 2 sets of wheels. One with summer tires and the other with the original wheels and all season radials. Each is the same within the set, but the sets are different from each other. When I change them from one set to the other the light will come on if I don't reset the tire sensor. It even comes on if I only take one wheel off and replace it. It's a simple enough thing to reset so I just do it.

 

According to the owner's manual, that is exactly how it works. Not positive but I think that's why they call it re-initializing instead of re-setting in the manual. It will remember the rotations of the tires, as they are when initialized, and will not light up until one or more tires has changed enough to set it off. That's why the new tire set it off.... it was significantly "larger" since it had new tread and the old one was a little less than half.

You have to be still until the light comes on for re-initialize. Then, once it is driven and the light goes off it is done. It's on page 73/74 of my owner's manual where they state that. (06 MCS manual)

 

Hope this can clear things up for anyone with further questions.
Straight from the manual > pdf file online at miniusa. https://ol.miniusa.com/publications/OwnManual/download_pdf.asp?file=2006_MINI.pdf -

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[/SIZE][/FONT][FONT=MiniThesis-Regular][SIZE=1]drive, without any feedback issued.
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You could have 4 different size tires on the car, after you reset the system. It senses change in tire size, not a constant difference in tire size. Put different air pressure in all 4 wheels, reset system, and it should not send a warning.

I have reset the system both standing still, and on the fly.

Mark

 

Wow. You learn something new every day.

 

Well that's how my brain thinks it works I have had a slow leak in a tire, reset the system, and it did not give a warning till the tire lost another couple of PSI. So that tells me that once you have reset, and it starts averaging out tire rotation, unless something changes, no warning.

I have reset the system both standing still, and on the fly.

Mark