Tire sensor is exactly .5 psi out of whack

BarryJI · 08-11-2015, 01:26 PM

Yes, I know this is very OCD on my part but I have now verified that either one of my front tire pressure sensors is inaccurate by .5 psi over or the other is by .5 psi under. I am just wondering, do any of you know if this can easily be recalibrated electronically, or will it involve replacing a part, in which case I will -- reluctantly -- live with the error? Many thanks.

pikcachu · 08-11-2015, 01:30 PM

I suppose there is an +/- error for the sensors .5 is probably around 1% which is probably as designed..

0.5 won't make your car jump the curb... but 1.5 might

so keep an eye

http://f80.bimmerpost.com/forums/sho....php?t=1075458

Pyewacket69 · 08-11-2015, 03:01 PM

Quote:

Originally Posted by BarryJI

Yes, I know this is very OCD on my part but I have now verified that either one of my front tire pressure sensors is inaccurate by .5 psi over or the other is by .5 psi under. I am just wondering, do any of you know if this can easily be recalibrated electronically, or will it involve replacing a part, in which case I will -- reluctantly -- live with the error? Many thanks.

Curious... How exactly have you verified the difference?

Air pressure gauges have several accuracy classifications, which might explain the variance.

What is the classification of the gauge you used?

Here's a link to a site that gives a basic explanation...

http://www.getagauge.com/faq.cfm

Cyberdemon · 08-11-2015, 03:43 PM

Everything in the world has a tolerance. I expect that is within their tolerance margin of error.

And yes, this would fall under the extreme OCD category.

Transfer · 08-11-2015, 04:28 PM

Quote:

Originally Posted by pikcachu

I suppose there is an +/- error for the sensors .5 is probably around 1% which is probably as designed..

0.5 won't make your car jump the curb... but 1.5 might

so keep an eye

http://f80.bimmerpost.com/forums/sho....php?t=1075458

Came here for this, wasn't disappointed.

BarryJI · 08-11-2015, 04:38 PM

Same here. Glad I could have been of assistance.

I tested the pressures with two high-end digital gauges immediately after two all-round tire refills. In each case, rear pressures were identical, and accurate to the last tenth but there has always been a .5 psi discrepancy on the fronts.

Xiaoxi · 08-11-2015, 04:43 PM

Isn't there a lot of variance depending on temperature?

Just last week I filled my tires to 33 front and 38 rear. Sometimes they will dip as low as 30/35, and are almost never identical / even.

pikcachu · 08-11-2015, 04:47 PM

Quote:

Originally Posted by Xiaoxi

Isn't there a lot of variance depending on temperature?

Just last week I filled my tires to 33 front and 38 rear. Sometimes they will dip as low as 30/35, and are almost never identical / even.

yes ...pressure changes about 1psi for every 10F change

pressure should be 32F 38F cold.... hot will always be higher like 35F 41F or so

Pyewacket69 · 08-11-2015, 04:48 PM

That's correct. Tires operate on the same physics as hot air balloons.

Xiaoxi · 08-11-2015, 04:49 PM

Looks like I'll need to spare another couple of quarters lol

Pyewacket69 · 08-11-2015, 05:11 PM

Quote:

Originally Posted by Xiaoxi

Looks like I'll need to spare another couple of quarters lol

I coded my M235 to display both PSI and tire temps, and I have seen the fronts start to change PSI readings as the engine warms up.

AFAIK, there isn't any way to keep all the tires uniformly pressured...

Xiaoxi · 08-11-2015, 05:36 PM

Do you even need to code for that?

Both temps and psi's show for me if I just hit vehicle status.

3.0L · 08-11-2015, 07:13 PM

I don't think .5 lbs. error is anything to get wrapped around the axle about. Our world is full of tolerances. I think this one is acceptable.

And then there's possible differences in your tire temperatures...

Pyewacket69 · 08-11-2015, 07:40 PM

Quote:

Originally Posted by Xiaoxi

Do you even need to code for that?

Both temps and psi's show for me if I just hit vehicle status.

My 2014 235 was delivered showing only PSI...

pikcachu · 08-11-2015, 07:44 PM

Quote:

Originally Posted by Pyewacket69

My 2014 235 was delivered showing only PSI...

It's really weird.... some show PSI and temp and some just PSI

artztt · 08-11-2015, 07:52 PM

Quote:

Originally Posted by pikcachu

It's really weird.... some show PSI and temp and some just PSI

Pikcachu Really? You out of everybody on this forum knows very well you need to code the vehicle (US spec) for it to show the temp. Stop Trolling!

pikcachu · 08-11-2015, 08:01 PM

Quote:

Originally Posted by artztt

Pikcachu Really? You out of everybody on this forum knows very well you need to code the vehicle (US spec) for it to show the temp. Stop Trolling!

No, really some cars come with the Temp stock....
First I thought it was a 2015 thing as some guys with 2015 started saying that they had temp with no coding, but then there are 2015 with no temp...

Not sure if its US or non-US related...

http://www.2addicts.com/forums/showp...10&postcount=9

http://www.2addicts.com/forums/showp...0&postcount=11

Pyewacket69 · 08-11-2015, 08:52 PM

Quote:

Originally Posted by pikcachu

Quote:

Originally Posted by artztt

Pikcachu Really? You out of everybody on this forum knows very well you need to code the vehicle (US spec) for it to show the temp. Stop Trolling!

No, really some cars come with the Temp stock....
First I thought it was a 2015 thing as some guys with 2015 started saying that they had temp with no coding, but then there are 2015 with no temp...

Not sure if its US or non-US related...

http://www.2addicts.com/forums/showp...10&postcount=9

http://www.2addicts.com/forums/showp...0&postcount=11

FWIW, my M235i was a 14 model delivered in May 28, 2014, manual transmission and completely optioned out, and I took delivery at the PC in Spartanburg, SC (8 miles from where I reside).

I personally coded the temperature to display. When it was delivered, all it displayed was PSI.

Maybe that info will be helpful...

nike001 · 08-11-2015, 09:32 PM

Mine displayed PSI & tire temp stock, FWIW.

I assume all you guys use stock inflation pressures?

BarryJI · 08-11-2015, 09:43 PM

Quote:

I assume all you guys use stock inflation pressures?

No, I go 2 PSI higher all round, so 34/40 for the staggered Michelin PSS tires in my 228i. I do this partially to compensate for the fact that because I do not have a compressor at home, my tires will be a little warm by the time I get to the garage. It also helps steering response and reduces roll but It's more out of habit than anything else.

nike001 · 08-11-2015, 09:59 PM

Quote:

Originally Posted by BarryJI

No, I go 2 PSI higher all round, so 34/40 for the staggered Michelin PSS tires in my 228i. I do this partially to compensate for the fact that because I do not have a compressor at home, my tires will be a little warm by the time I get to the garage. It also helps steering response and reduces roll but It's more out of habit than anything else.

I'm at like 38/41. I've found the recommended pressures were waaay too low. Sloppy turn-in, body roll etc. Much more sure-footed with higher pressures.

German1967 · 08-12-2015, 05:31 AM

Quote:

Originally Posted by nike001

Mine displayed PSI & tire temp stock, FWIW.

I assume all you guys use stock inflation pressures?

Same. May 2015 built.

08-11-2015, 01:26 PM	#1
BarryJI Captain 428 Rep 980 Posts Drives: 2015 BMW 228i M Sport Join Date: Apr 2015 Location: United States iTrader: (0)	Tire sensor is exactly .5 psi out of whack Yes, I know this is very OCD on my part but I have now verified that either one of my front tire pressure sensors is inaccurate by .5 psi over or the other is by .5 psi under. I am just wondering, do any of you know if this can easily be recalibrated electronically, or will it involve replacing a part, in which case I will -- reluctantly -- live with the error? Many thanks. __________________ 2015 BMW 228i M Sport w/Track Handling Package DAP \| Lighting \| Premium \| Tech DINANTRONICS Performance Tuner Stage 1 \| DINAN Shockware \| DINAN Free Flow Exhaust \| DINAN Performance Spring Set + Ride Quality and Handling Kit
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08-11-2015, 01:30 PM	#2
pikcachu Major General 1412 Rep 5,262 Posts Drives: M235i (F22 Red angel) Join Date: Jul 2011 Location: undisclosed iTrader: (1)	I suppose there is an +/- error for the sensors .5 is probably around 1% which is probably as designed.. 0.5 won't make your car jump the curb... but 1.5 might so keep an eye http://f80.bimmerpost.com/forums/sho....php?t=1075458
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08-11-2015, 03:43 PM	#4
Cyberdemon Brigadier General 1542 Rep 3,338 Posts Drives: 2020 X5 40i, 2018 M3 Comp Join Date: Jun 2012 Location: Long Island NY iTrader: (3)	Everything in the world has a tolerance. I expect that is within their tolerance margin of error. And yes, this would fall under the extreme OCD category. __________________ Current: '20 X5, '18 M3 ZCP Previous: '11 E90 335i, '11 E90 M3, '16 VW GTI, '15 M235i, '13 335i, '08 TL-S, '00 Corvette
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08-11-2015, 04:38 PM	#6
BarryJI Captain 428 Rep 980 Posts Drives: 2015 BMW 228i M Sport Join Date: Apr 2015 Location: United States iTrader: (0)	Same here. Glad I could have been of assistance. I tested the pressures with two high-end digital gauges immediately after two all-round tire refills. In each case, rear pressures were identical, and accurate to the last tenth but there has always been a .5 psi discrepancy on the fronts.
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08-11-2015, 04:43 PM	#7
Xiaoxi Lieutenant 272 Rep 470 Posts Drives: a Miata Join Date: Jul 2014 Location: DC metro iTrader: (0)	Isn't there a lot of variance depending on temperature? Just last week I filled my tires to 33 front and 38 rear. Sometimes they will dip as low as 30/35, and are almost never identical / even. __________________ 2015 M235i \| AW \| 6MT \| Tech \| Heated Seat \| Parking Assist \| Fabspeed DP & Muffler Delete \| Apex PS7s 1999 MX5 NB \| Emerald Mica \| 5MT \| Sport Edition \| Kosei K5Rs \| Heated Rear Glass ig: @bee2ven
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08-11-2015, 04:48 PM	#9
Pyewacket69 Second Lieutenant 76 Rep 288 Posts Drives: 2014 M235i Join Date: Apr 2015 Location: South Carolina USA iTrader: (0)	That's correct. Tires operate on the same physics as hot air balloons.
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08-11-2015, 04:49 PM	#10
Xiaoxi Lieutenant 272 Rep 470 Posts Drives: a Miata Join Date: Jul 2014 Location: DC metro iTrader: (0)	Looks like I'll need to spare another couple of quarters lol __________________ 2015 M235i \| AW \| 6MT \| Tech \| Heated Seat \| Parking Assist \| Fabspeed DP & Muffler Delete \| Apex PS7s 1999 MX5 NB \| Emerald Mica \| 5MT \| Sport Edition \| Kosei K5Rs \| Heated Rear Glass ig: @bee2ven
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08-11-2015, 05:36 PM	#12
Xiaoxi Lieutenant 272 Rep 470 Posts Drives: a Miata Join Date: Jul 2014 Location: DC metro iTrader: (0)	Do you even need to code for that? Both temps and psi's show for me if I just hit vehicle status. __________________ 2015 M235i \| AW \| 6MT \| Tech \| Heated Seat \| Parking Assist \| Fabspeed DP & Muffler Delete \| Apex PS7s 1999 MX5 NB \| Emerald Mica \| 5MT \| Sport Edition \| Kosei K5Rs \| Heated Rear Glass ig: @bee2ven
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08-11-2015, 07:13 PM	#13
3.0L Colonel 9794 Rep 2,010 Posts Drives: 2014 BMW M235i, 2024 GLC300 Join Date: Apr 2014 Location: California iTrader: (0)	I don't think .5 lbs. error is anything to get wrapped around the axle about. Our world is full of tolerances. I think this one is acceptable. And then there's possible differences in your tire temperatures... __________________ 2014 BMW M235i 2024 Mercedes Benz GLC300 Expert ultracrepidarian
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08-11-2015, 09:32 PM	#19
nike001 Captain 330 Rep 823 Posts Drives: 2018 718 Cayman Join Date: Apr 2011 Location: US iTrader: (2)	Mine displayed PSI & tire temp stock, FWIW. I assume all you guys use stock inflation pressures?
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