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[hipnotic]

I have after wheels with tpms mounted inside. My question is that every morning does not matter if I park inside or outside the garage my tpms light comes on my dashboard. I have tried to reset the tpms by holding the button on the left and it says reset. But as I continue to drive the tpms light does not turn off. However if I drive my car for 30 minutes or so and try to reset it. The tpms indicator light will go off my dashboard. Do you guys know if the tpms is malfunction, am I resetting wrong, or what do you think is happening? Any help will be appreciated. I do not think that it is malfunction because it does go away when the tires are heated but for some reason I am not able to reset it when it is cold outside. By the way I live in So. Cali so the weather is not as crazy as the east coast. Please let me know. Thanks

[Tom K.]

What were your tire pressures when you got the warnings? And what were the baseline pressures (the psi when the TPMS was reset)?

Tom

[hipnotic]

I am not sure. I know that if the psi change a little bit it will trigger the light. But I thought if you drive it and as the wheel rotates that it will warm up the tires and the psi will increase. That is why I didn't bother checking.

[hipnotic]

You think that it if I put more air in the tires that the tpms will go away? I believe it was set somewhere around 38 and 40 but not sure. What do you think?

[Clarence Watson]

Originally Posted by josh06lau

You think that it if I put more air in the tires that the tpms will go away? I believe it was set somewhere around 38 and 40 but not sure. What do you think?

Try it and see. Another possibility, which might seem obvious, is that you have a slow pressure leak. Are you measuring pressure each time before and after you add air to the tires (assuming you ever add air)?

[anerbe]

I believe with the TPMS, it will light with either a difference in tire pressure, or absolute tire pressure per tire.

The old ABS system in the E46 only read by wheel speed difference, so if all 4 tires were low it wouldn't trip.

You could be at the border for tire pressure, either on the low or high side. Set your cold pressures to the values in the door sill. See if it still goes off. If so, you may have a bad sensor or system.

[hipnotic]

So I should wait about 2 hours to let the tires cool down after it has been driven and then check the tire pressure. Also, I was reading about a check mark when it resets. I hold the button for 5 seconds without driving and I don't get a check mark.

[ceb]

Originally Posted by josh06lau

I am not sure. I know that if the psi change a little bit it will trigger the light. But I thought if you drive it and as the wheel rotates that it will warm up the tires and the psi will increase. That is why I didn't bother checking.

Do you understand the purpose of TPMS? It is to alert you to a severely underinflated tire (or in your case possibly tires) and the system won't reset if the tires are severely low.

Go to an auto parts store and buy the best tire gauge you can afford

Go to a gas station and add the correct amount of air to your tires. Fronts will have less pressure than the rears and the correct amount can be found on a placard on your driver's side door jamb.

Reset the system

Enjoy

Let me explain (again) how the system works. By law, a TPMS sensor in the US must alert you if the pressure in any tire (excluding the spare) drops at least 25%.

This means that your tire pressure in at least one tire is under 28psi (if 38 is "normal") or about 26 for the front tires.

I'm not sure what the bottom limit for for BMW is (where the system will refuse to reset) but it is probably around 30% below the lowest proper inflation pressure of any US bound 3 series.

Me, I'd inflate the rears to a few psi above the recommended pressure, reset the system and then adjust the pressure to the correct amount.

[Ryan_L_330I]

i might be misunderstanding you but go try this, go to the tpms reset on the stalk. When you press the button the first time it confirms that you want to reset. You then have to press and hold for 5 seconds to reset. So get into your car if you get the light reset it, just ensure that your tire pressure is correct before you do. I had the same issue last month when i was in vermont, it was a lot colder than kingston and i had to check the tires because i thought i had damaged a tire but it was just the fluctuation in pressure among all the tires.

let me know if this helps

ryan

[hipnotic]

yeah I held the BCU system for 5 seconds and it says that it is resetting but after I begin driving it alerts me about the tpms. I will try to check it tomorrow and hopefully it will resolve this problem. I hate seeing the warning light on my display

[ctuna]

Do they eventually need replacing due to age ?

[ceb]

Originally Posted by ctuna

Do they eventually need replacing due to age ?

The batteries are non-replaceable and the sensors will need to be replaced every 6-7 years.

[Ryan_L_330I]

try pressing the button once to activate then hold the button again for 5 seconds to reset until you get the check mark

[hipnotic]

i don't get a check mark though.