[nfwb11]

Picked up my '14 435i a month ago and finally got around to peeking into all the intricate details the Connected Drive provides. But when I was able to get into the TPS I discovered an issue (w/ Forgman's help). The sticker on the inside driver door indicates the following PSI:

Front: 35 PSI
Rear: 38 PSI

As you can see by pic #2 (sorry for poor iPhone quality) the PSI is too high at 39+ on the fronts -- maybe they didn't adjust from the shipping PSI?

Front Right: 39.2 PSI
Front Left: 39.5 PSI
Rear Right: 39.2 PSI
Rear Left: 39.2 PSI

Naturally, I went to the gas station to deflate the tires down to the specified PSI; problem solved right? Actually, this presented a new problem. I deflated to get closer to advised levels and now TPS issues warnings that PSI is too low:

Front Right: 34.8 PSI (35 is advised)
Front Left: 37 PSI (35 is advised)
Rear Right: 40.3 PSI (38 is advised)
Rear Left: 40.3 PSI (38 is advised)

I ran the check with the car/tires fairly cold as advised by BMWNA. Didn't even touch the rears but now they are considered too low as well. So I'm left wondering WTF is going on with this?

[zeezz]

hm, that's very odd. I don't have NBT, but mine dip down to the low 30's with no issues...

[HighlandPete]

Why not set them up to the recommended pressure and take another look at the TPS.

Your front tires are over 2 psi different side to side, that is an error.

HighlandPete

[DTRJ]

Originally Posted by nfwb11

Picked up my '14 435i a month ago and finally got around to peeking into all the intricate details the Connected Drive provides. But when I was able to get into the TPS I discovered an issue (w/ Forgman's help). The sticker on the inside driver door indicates the following PSI:

Front: 35 PSI
Rear: 38 PSI

As you can see by pic #2 (sorry for poor iPhone quality) the PSI is too high at 39+ on the fronts -- maybe they didn't adjust from the shipping PSI?

Front Right: 39.2 PSI
Front Left: 39.5 PSI
Rear Right: 39.2 PSI
Rear Left: 39.2 PSI

Naturally, I went to the gas station to deflate the tires down to the specified PSI; problem solved right? Actually, this presented a new problem. I deflated to get closer to advised levels and now TPS issues warnings that PSI is too low:

Front Right: 34.8 PSI (35 is advised)
Front Left: 37 PSI (35 is advised)
Rear Right: 40.3 PSI (38 is advised)
Rear Left: 40.3 PSI (38 is advised)

I ran the check with the car/tires fairly cold as advised by BMWNA. Didn't even touch the rears but now they are considered too low as well. So I'm left wondering WTF is going on with this?

Are you using a high quality tire gauge? The $2 ones are usually inaccurate, and the ones at the air pump are even worse. I would try another gauge first.

[ERdiesel]

Did you reset the TPS after deflating the tires? If not, you should.

[EBS0712]

The TPMS system is designed to warn when a tire loses pressure so it is more important to measure pressure differential rather than the actual pressure measurement. Set the pressure to the recommended levels (photo #1) using a quality pressure gauge and then reset the TPMS system per the instructions in the manual. This will remove the low pressure warning. Forget about the inaccuracy in the pressure readings (photos #2 & 3) and just worry if you get a low pressure reading indicating that a tire has lost pressure (pressure differential measured). It is also possible to get the low pressure warning if you reset the TPMS with normal cold temps (60's) and then leave the car out on a really cold night (blow zero). This is normal to lose pressure in the tire due to lower tire temperature.

[Frogman]

Originally Posted by nfwb11

Picked up my '14 435i a month ago and finally got around to peeking into all the intricate details the Connected Drive provides. But when I was able to get into the TPS I discovered an issue (w/ Forgman's help). The sticker on the inside driver door indicates the following PSI:

Front: 35 PSI
Rear: 38 PSI

As you can see by pic #2 (sorry for poor iPhone quality) the PSI is too high at 39+ on the fronts -- maybe they didn't adjust from the shipping PSI?

Front Right: 39.2 PSI
Front Left: 39.5 PSI
Rear Right: 39.2 PSI
Rear Left: 39.2 PSI

Naturally, I went to the gas station to deflate the tires down to the specified PSI; problem solved right? Actually, this presented a new problem. I deflated to get closer to advised levels and now TPS issues warnings that PSI is too low:

Front Right: 34.8 PSI (35 is advised)
Front Left: 37 PSI (35 is advised)
Rear Right: 40.3 PSI (38 is advised)
Rear Left: 40.3 PSI (38 is advised)

I ran the check with the car/tires fairly cold as advised by BMWNA. Didn't even touch the rears but now they are considered too low as well. So I'm left wondering WTF is going on with this?

Your tires were at something like 42 psi when we coded your car.

When you dropped the pressure to "normal", TPMS triggered an alert because the pressure was too much lower than when it was last reset. TPMS does not know your proper pressure, only that it's lower than the last time it was reset.

So, after setting the pressure properly, you must always reset the TPMS to tell it that this is the "correct" pressure now.

[nfwb11]

Originally Posted by Frogman

Your tires were at something like 42 psi when we coded your car.

When you dropped the pressure to "normal", TPMS triggered an alert because the pressure was too much lower than when it was last reset. TPMS does not know your proper pressure, only that it's lower than the last time it was reset.

So, after setting the pressure properly, you must always reset the TPMS to tell it that this is the "correct" pressure now.

Correct. Ultimately, I had to do several resets to get consistent readings. Still not perfect, but here's the readout after running a reset on cold tires -- I'm in the wheelhouse so-to-speak.

[cailas]

Just fill the tires with nitrogen and you will forget about pressure changing when the weather gets colder/warmer.

[ATX78703]

hey how did you get actual numbers? coding? or is that a 4 series thing?

[Fille]

Originally Posted by ATX78703

hey how did you get actual numbers? coding? or is that a 4 series thing?

I'm wondering this too... If it's just a coding thing then BMW can stick it. That's just a cheap move. .

[ronin951]

Originally Posted by Fille

I'm wondering this too... If it's just a coding thing then BMW can stick it. That's just a cheap move. .

+2

[Dippydo]

Originally Posted by Fille

I'm wondering this too... If it's just a coding thing then BMW can stick it. That's just a cheap move. .

Yes it can be done through coding in the 3 series. Just need to find someone around me that can do it..

[nfwb11]

Originally Posted by ATX78703

hey how did you get actual numbers? coding? or is that a 4 series thing?

Coding. Very cool feature but someone OCD about their ride (like me ) may prefer the "ignorance is bliss" approach and just trust the car.

[s0nu]

Originally Posted by nfwb11

Coding. Very cool feature but someone OCD about their ride (like me ) may prefer the "ignorance is bliss" approach and just trust the car.

This would be me