How accurate is the tire monitoring system?

Chicks-Love-Bimmers · 07-22-2010, 11:51 AM

Well when I got in my car today I started it, and the navigation screen said that my left rear tire had low pressure. I got out and tried to check to see if it had any air and it seemed okay just like the rest of my other tires. Is the tire monitoring system pretty accurate or should I just ignore it?

SilvrnBlk325i · 07-22-2010, 11:54 AM

Did you actually check it with a Tire pressure monitor or just look at the tire?? Cause sometimes it may look okay but actually is low in pressure! I would check it just in-case! Those monitoring systems are usually pretty accurate!

Chicks-Love-Bimmers · 07-22-2010, 11:59 AM

No I just went out and pressed against the tires to see if there was air in it and it seemed okay to me, but the onboard tire monitor system said that it had low pressure.

E90 87ss · 07-22-2010, 12:00 PM

Invest in tire pressure gauge. $5.00... Yes it is accurate, you are probably low at least 5-10 psi probably more.

alex2364 · 07-22-2010, 12:05 PM

It's a lot more accurate than pressing your finger.

Chicks-Love-Bimmers · 07-22-2010, 12:05 PM

Thank you for the feedback guys, I guess I'm off to discount tires.

Edward · 07-22-2010, 12:08 PM

I usually knock on my engine cover to find out if I have enough oil.

Joonsup · 07-22-2010, 12:31 PM

Quote:

Originally Posted by Edward

I usually knock on my engine cover to find out if I have enough oil.

when my tire pressure is off by around 5psi the system lets me know

coh4777 · 07-22-2010, 01:27 PM

You def need a pressure guage to check your tires like others have said. I keep one in my center console. Also know that electrical interferance can sometimes trip your TPMS, so if you check your pressure and it is good, just reset the system. These false alarms are rare but I have had a couple in the past year.

Everling · 07-23-2010, 02:31 AM

Quote:

Originally Posted by Chicks-Love-Bimmers

No I just went out and pressed against the tires to see if there was air in it and it seemed okay to me, but the onboard tire monitor system said that it had low pressure.

serious? this isnt a bicycle tire man...

cstavaru · 07-23-2010, 03:08 AM

Quote:

Originally Posted by Edward

I usually knock on my engine cover to find out if I have enough oil.

Runflat tires do not ever seem to be flat by looking at them...

dcg71 · 07-23-2010, 08:00 AM

yep, a runflat at 10psi doesn't look or feel much different to one at 40psi.

Oddball · 07-23-2010, 08:11 AM

I'm not too impressed with my sensors. After having the car for three weeks, I ran over some debris on the highway. The front tires were replaced with non-run flats. Front tire immediately blew out. After limping to a tire shop, we discovered the rear run flat was also blown when i told them to check all 4 tires. Tire pressure system said nothing. I almost replaced just the front and drove off with a blown rear.

It only went off AFTER I had 4 new tires on the car and drive for an additional 10 miles. Wouldn't you expect it to detect the complete loss of pressure immediately?

When we took the wheels off, there were no sensors in the wheels. How does the system work?

mmmmQuattro · 07-23-2010, 08:12 AM

I thought that they only monitor a sudden pressure drop.
Anyway I had a runflat wear out after only 3,000 miles because it was at 30psi rather than 40psi.
I now own the $5 pressure gauge and check the pressure every couple of weeks.

skier · 07-23-2010, 09:33 AM

Quote:

Originally Posted by jp330Cic.au

I thought that they only monitor a sudden pressure drop.

Nope, it monitors any pressure drop below a threshold. I usually reset the TPM at 44psi, and get alerts if tire pressure drops below 35psi.

Looking at your signature, it could differ between markets - my car is a 2009 with iDrive.

skier · 07-23-2010, 09:37 AM

Quote:

Originally Posted by Chicks-Love-Bimmers

No I just went out and pressed against the tires to see if there was air in it and it seemed okay to me, but the onboard tire monitor system said that it had low pressure.

One doesn't kick tires anymore, get a gauge as others suggested.

07-22-2010, 11:51 AM	#1
Chicks-Love-Bimmers Captain 68 Rep 743 Posts Drives: FBO 335i Join Date: May 2010 Location: Bellevue, Washington iTrader: (6) Garage List 2007 E92 335i [0.00]	How accurate is the tire monitoring system? Well when I got in my car today I started it, and the navigation screen said that my left rear tire had low pressure. I got out and tried to check to see if it had any air and it seemed okay just like the rest of my other tires. Is the tire monitoring system pretty accurate or should I just ignore it?
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07-22-2010, 11:54 AM	#2
SilvrnBlk325i Private First Class 7 Rep 138 Posts Drives: E90 325i Join Date: May 2010 Location: Las Vegas iTrader: (2)	Did you actually check it with a Tire pressure monitor or just look at the tire?? Cause sometimes it may look okay but actually is low in pressure! I would check it just in-case! Those monitoring systems are usually pretty accurate!
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07-22-2010, 11:59 AM	#3
Chicks-Love-Bimmers Captain 68 Rep 743 Posts Drives: FBO 335i Join Date: May 2010 Location: Bellevue, Washington iTrader: (6) Garage List 2007 E92 335i [0.00]	No I just went out and pressed against the tires to see if there was air in it and it seemed okay to me, but the onboard tire monitor system said that it had low pressure.
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07-22-2010, 12:00 PM	#4
E90 87ss Captain 37 Rep 608 Posts Drives: ! Join Date: Sep 2009 Location: NJ/Philly iTrader: (1)	Invest in tire pressure gauge. $5.00... Yes it is accurate, you are probably low at least 5-10 psi probably more.
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07-22-2010, 12:05 PM	#5
alex2364 Colonel 2880 Rep 2,761 Posts Drives: 2020 M4 ZCP / 2023 X3 M40i Join Date: May 2005 Location: Northern VA iTrader: (2) Garage List 2020 BMW M4 [10.00] 2023 BMW X3 M40i [10.00]	It's a lot more accurate than pressing your finger.
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07-22-2010, 12:08 PM	#7
Edward Colonel 377 Rep 2,982 Posts Drives: 2013.9999 E92 Jerez ZCP Join Date: May 2010 Location: Los Angeles iTrader: (2)	I usually knock on my engine cover to find out if I have enough oil.
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07-22-2010, 01:27 PM	#9
coh4777 Lieutenant 29 Rep 533 Posts Drives: 07 BMW 335i Coupe Join Date: Jul 2009 Location: Vegas iTrader: (0)	You def need a pressure guage to check your tires like others have said. I keep one in my center console. Also know that electrical interferance can sometimes trip your TPMS, so if you check your pressure and it is good, just reset the system. These false alarms are rare but I have had a couple in the past year. __________________ COH4777 2007 335i Coupe - Jet Black / Coral Red / Aluminum Trim / 6MT / Sport / Premium / CA / Navi / iPod + USB
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07-23-2010, 08:00 AM	#12
dcg71 Captain 72 Rep 941 Posts Drives: F15 X5 Join Date: Jul 2009 Location: Brisbane, Australia iTrader: (2)	yep, a runflat at 10psi doesn't look or feel much different to one at 40psi.
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07-23-2010, 08:11 AM	#13
Oddball New Member 0 Rep 6 Posts Drives: 1986 Chevy IROC, 2006 330xi Join Date: Jul 2010 Location: South Jersey iTrader: (0)	I'm not too impressed with my sensors. After having the car for three weeks, I ran over some debris on the highway. The front tires were replaced with non-run flats. Front tire immediately blew out. After limping to a tire shop, we discovered the rear run flat was also blown when i told them to check all 4 tires. Tire pressure system said nothing. I almost replaced just the front and drove off with a blown rear. It only went off AFTER I had 4 new tires on the car and drive for an additional 10 miles. Wouldn't you expect it to detect the complete loss of pressure immediately? When we took the wheels off, there were no sensors in the wheels. How does the system work? __________________ The lone tree on the distant mountain always looks taller when the grass is mowed.
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07-23-2010, 08:12 AM	#14
mmmmQuattro Major 259 Rep 1,165 Posts Drives: f83 / E93 335 / E70 X5 40d Join Date: Sep 2007 Location: Adelaide, South Australia iTrader: (0) Garage List 2007 320 E91 M-Spor ... [0.00] 2009 335-E93 M-Sport [0.00]	I thought that they only monitor a sudden pressure drop. Anyway I had a runflat wear out after only 3,000 miles because it was at 30psi rather than 40psi. I now own the $5 pressure gauge and check the pressure every couple of weeks.
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