2004 E46 M3 - Tyre pressure monitor

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Mon 20 May 2013 14:15
2004 E46 M3 - Tyre pressure monitor - redstripe
Hi, my tyre pressure monitor light on dash keeps coming on but the tyre pressures are ok. All that has changed is that I have put a full set of new tires on has anyone ever come across this problem or do you think it's just a coincidence and I've got another problem, look forward to hearing your reply's.
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Mon 20 May 2013 14:30
2004 E46 M3 - Tyre pressure monitor - Cyd

You did follow the proceedure in the owners manual to reset the monitor, didn't you? You need to do this each time pressures are adjusted or new tyres fitted.

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Mon 20 May 2013 15:37
2004 E46 M3 - Tyre pressure monitor - redstripe
Yes I've done it many times before every couple of weeks with no problem, but now it only stays off for a few minutes or couple of miles. With changing the tires it has me thinking but I do think very deeply and don't believe in coincidences.
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Mon 20 May 2013 16:33
2004 E46 M3 - Tyre pressure monitor - Peter D

Did the tyre fitter put the rim back on the same wheel. Regards Peter

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Tue 21 May 2013 10:20
2004 E46 M3 - Tyre pressure monitor - redstripe
To be honest I don't know, i appreciate your answer but how does this affect the sensors as there is nothing on the wheels themselves ( or is there )? I do have offset wheels on so it would mean only swapping the fronts or backs over if this could be the problem, I just like to understand why I'm doing something cheers.
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Tue 21 May 2013 11:47
2004 E46 M3 - Tyre pressure monitor - TeeCee

as there is nothing on the wheels themselves ( or is there )?

Er, the sensor has to be inside the tyre to know what the pressure is. Rather idiotically, these systems tend to be organised so that each corner has to have the right wheel (and therefore sensor) on it.

I sometimes think that some of these systems put on new cars must be designed by people who have never owned a car.....

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Tue 21 May 2013 15:16
2004 E46 M3 - Tyre pressure monitor - redstripe


Er, the sensor has to be inside the tyre to know what the pressure is.



This type of system on this BMW M3 does not use actual pressure in each tyre the system actually picks up a wheel that is not turning at the same rate as the others, a tyre that is deflated turns slower than a correctly inflated one!! So there is no need for anything inside the tires
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Tue 21 May 2013 17:32
2004 E46 M3 - Tyre pressure monitor - madf
Er, the sensor has to be inside the tyre to know what the pressure is. This type of system on this BMW M3 does not use actual pressure in each tyre the system actually picks up a wheel that is not turning at the same rate as the others, a tyre that is deflated turns slower than a correctly inflated one!! So there is no need for anything inside the tires

So a single new tyre - with a larger rolling diameter than three worn ones - may trigger a reading? Or is the difference in radius too small?

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Tue 21 May 2013 20:05
2004 E46 M3 - Tyre pressure monitor - redstripe
You reset the system every time you change something whether its blowing the tires up or changing a wheel or tyre. This way it is just simply remembering the current readings and tells you when one alters, so one tyre wouldn't matter.
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Wed 22 May 2013 09:36
2004 E46 M3 - Tyre pressure monitor - TeeCee
Er, the sensor has to be inside the tyre to know what the pressure is. This type of system on this BMW M3 does not use actual pressure in each tyre the system actually picks up a wheel that is not turning at the same rate as the others, a tyre that is deflated turns slower than a correctly inflated one!! So there is no need for anything inside the tires

Aha! So in that case: a) It shouldn't give a monkey's which wheel is on which corner. b) The warning could be triggered by a brief loss of grip, tight cornering or anything else that causes a difference in wheel speed, so intermittant false alarms should be expected??

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Wed 22 May 2013 10:30
2004 E46 M3 - Tyre pressure monitor - Collos25

These are on my sons 330 as far as I know they are programed to each wheel position and they detect a difference in the diameter of the wheel and tyre,Iknow that when I put the wheels in a different position the computer detected it was in the wrong position wether this is the same on all BMWc I would not know. The sensors are easily damaged during tyre a change and they never seem to work correctly haaving been back to BMW under warranty a few times with the same problem.

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Wed 22 May 2013 13:23
2004 E46 M3 - Tyre pressure monitor - redstripe
Oh well, from what I've read here and else where there doesn't seem to be a single reliable tyre pressure monitor system out there. This flabbergasts me, looks like these are just an unreliable optional extra on most cars. Thanks for the reply's. I will just disable mine even though it is a great tool for my very low profile tires which you can't tell the difference unless they are totally flat.

PS slight loss of grip does not set these off it has to be for a certain length of time to register but don't know how long, but I have known mine to go off on a long stretch of road which has had two types of road surface and the near side wheels have been on one surface and the offside on the other. So they must be pretty sensitive. Thanks anyway it everyone !!!!
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