Baloo588

I have done the storing of the current tire pressures several times over the past few days while parked but I cannot even view my tire pressure at each 4 tires? How come?

L0U

are you sure it is even supossed to show the pressure indications? I was under the impression it alarms only when off setpoint...not indicating live time.

jakematic

It does not display on the D4 - only shows idiot light.

My OCD checking of it twice daily is in need of something else to do...

Baloo588

Wow I am a bit upset that they took away a neat feature from the D3 and dumbed it down for the D4. I do not like this one bit and feel that I need to make sure the pressures are good every few weeks without having to check each individually all the time.

derfA8L

Since all cars having TPMS must now have all replacement wheels with sensors (if a wheel sensor based system) you would have to have the units installed on winter tire rims and deal with having to replace the battery packs in the sensors every few years---all these issues are a fairly expensive proposition. Audi went to a simpler solution that works off the ABS system sensors that addresses the primary function of the TPMS: to warn you of a loss of air pressure in the tire(s). For many owners, a better setup in the long run. Had the wheel sensors in my prior two D3s and never used/trusted the TPMS pressure readings---always used my trusty pressure gauge every week; a bit of bending and stretching is good for my aging body ;-)

jakematic

Thanks for clarifying derf - I read something similar in the A7 forum referencing this thread.

Is there any documentation available as to how this works ?
I fail to see how ABS could do anything (useful) to detect tire pressures other than see that a wheel speed had changed.

For the record the TMPS sensors tend to last 5 years, and I would be more than willing to pay for actual numbers.
150 * 4 = $600
600 / 99,975 = not a hell of a lot

This isn't a Camry we're talking about after all

derfA8L

You're right, the sensor batteries or adding additional winter wheel units isn't that expensive, it's just an annoyance for something that is useful only to get the additional pressure read-out function (versus just a pressure loss indication) that most A8 drivers probably don't use that much, if at all. Audi simplified the functionality by limiting it to just a notification of loss of air pressure---and probably saved themselves some expense to boot. As for how the system works with ABS: (from the owner's manual) "Using the ABS sensors, the tire pressure monitoring system compares the tire tread circumference and vibration characteristics of the indvidual tires. If the pressure decreases in one or more tires, this is indicated in the instrument cluster with a warning symbol and a message."

jakematic

This is true - many folks in the D3 (and other) forums use VCDS to disable TPMS.

As usual I'm the exception and looooooved how they reamined perfect after the nitrogen fill
It was convenient to keep and eye on the temperatures during long trips in warmer climes.

scottphillip

I liked that feature in my D3. Did it not include the spare tire also?

The Lexus LS has it. My last BMW would indicate which tire was low, but not the actual pressure.

I noticed the new Cadillac XTS has the pressure displayed.

We have progress in the driver awareness features, etcetera, yet we lose full size spares and the fancy TPMS.

jakematic

Yes it did.
A low spare tire pressure was my first acquaintance with TPMS.

Combination of meeting a price point and the dumbing down of America, in my opinion.
They want an "airbag society" to protect themselves from everything, but not too much information so they actually have to think.