The “Run Flat Indicator� sometimes issues a warning erroneously. I was driving on packed snow on a paved road at 30-40 mph and the multifunction display stated “Tire pressure, Check tires!� I checked the tires and they were all at 28 psi. 32 psi is the recommended inflation for my tires so they were all 4 lbs low, at least according to the gauge I used to test them. However the “Run Flat Indicator� is expected to issue a warning when one or more of the tires is “significantly under-inflated. Accordingly the message was in error, imho. However, in reading the manual it states that the indicator may error in the following circumstances:
Snow Chains
Winter Conditions
Driving on sand or gravel
Driving in a sporty manner
To my knowledge my tires were not spinning on the flat surface of the road so the message should not have been displayed.
So just a heads-up on this warning!
btw the “Run Flat Indicator� has to be reset after the warning appears.
The system is not perfect, since it's interpreting inflation via wheel rotation instead of directly reading the pressure. Both my BMW and Mercedes have occasional false errors (as well as American rental cars I've driven), but it doesn't happen too often. I know tha manual calls it Run Flat Indicator, but since the ML does not have run flat tires, it's a bit of a misnomer. Tire pressure indicator would be better.
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<B>Greg</B> Lake Oswego, Oregon, USA
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<B>2006 ML350</b> - Pewter/Charcoal Alcantara/Aluminum; Packages: Comfort, Lighting, Entertainment, Appearance, Airmatic, Sunroof; Options: Nav, Sirius, hitch, heated seats, power liftgate, roof rack; Mods: ML500 skid plates, ML63 20" wheels.
<B>2001 BMW M3 Coupe</B> (5/01 prod.) - Titanium/Cinnamon w/ many mods.
Here is another example of the sensitivity of the system. I recently had my stock wheels changed to 18" twin spokes. After I left the dealer ship and went about a mile I got the same error. When I got home and checked the pressures, the tires were at 45 lbs each (storage Pressure) the mechanic didn't bother to check the pressure when he swapped out the wheels.
The system compared the rotational speed of the original 17" wheels and tires which were at 32 lbs to the new ones at 45 lbs. (The circumference is the same for the sets of tires and wheels so that wasn't the problem)
I set the air pressure back to 32 and reset the Run Flat Indicator and it hasn't appeared since.[:D]
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Andy
2006 ML350
723 - Pewter, 104 - Macadamia Interior, H04 - Brown Birds Eye Maple Wood, 167 Standard Non-Sport Pkg, 317 Comfort Pkg, 318 - Trim Package, 319 - Lighting Package, 320 - Entertainment Pkg, 324 - Sunroof Pkg, 580 - Std. Climate Control, 873 - Heated Front Seats, 890 - Power Liftgate, Navigation System, iPod interface kit
Modifications:
Added: Chrome Door handle cups, MB Twin Spoke 5-Spoke 18" wheels and tires
Here is another example of the sensitivity of the system. I recently had my stock wheels changed to 18" twin spokes. After I left the dealer ship and went about a mile I got the same error. When I got home and checked the pressures, the tires were at 45 lbs each (storage Pressure) the mechanic didn't bother to check the pressure when he swapped out the wheels.
The system compared the rotational speed of the original 17" wheels and tires which were at 32 lbs to the new ones at 45 lbs. (The circumference is the same for the sets of tires and wheels so that wasn't the problem)
I set the air pressure back to 32 and reset the Run Flat Indicator and it hasn't appeared since.[:D]
Interesting. It must keep the rotational data in memory otherwise it shouldn't give you an error if it is comparing rotational speed of the four tires for any variance between each tire because all your tires had the same inflation.
Interesting. It must keep the rotational data in memory otherwise it shouldn't give you an error if it is comparing rotational speed of the four tires for any variance between each tire because all your tires had the same inflation.
Yes that is what my salesman told me that way it can warn you if all 4 tires loose similar amounts of air. In the winter I find that I always have to add air to the tires because of the cooler temperatures.
On my ML (front driver-side door), cold pressure recommendation is 32 psi in front and 39 psi for the rears. Is this different for other MLs out there? Ibc posted 29 and 32 for his. Also, is the recommendation tire specific, or vehicle specific?
On my ML (front driver-side door), cold pressure recommendation is 32 psi in front and 39 psi for the rears. Is this different for other MLs out there? Ibc posted 29 and 32 for his. Also, is the recommendation tire specific, or vehicle specific?
The 32 front and 39 rear are for fully loaded. You can check on the inside of your gasoline flap and see picture of car with 3 people and 32,32 and then with more people and 32,39.
On page 346 of manual it states pressures only for original equipment tires.
On my ML (front driver-side door), cold pressure recommendation is 32 psi in front and 39 psi for the rears. Is this different for other MLs out there? Ibc posted 29 and 32 for his. Also, is the recommendation tire specific, or vehicle specific?
As lbc says it's 32/32 for normal loads. The rear pressure needs to be increased for load carrying at higher loads. It is tied to the vehicle design. Changing tires to different aspect ratios or widths may require slightly different pressures, but not much.
Does anybody know what the correct inflation is for the 18" tires and wheels? My salesman indicated that he would have to get me a new sitcker for the gas cap door.
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