Re: 2016 Outback 3.6 dashboard

<[email protected]> wrote:

> Do all new cars have this TPMS system?   Does replacing a tire consist
> of a trip to a tire dealer plus a trip to a car dealer?   Or does the
> tire dealer eal with the TPMS also?  All this I don't want or need.

TPMS has been mandated in the USA since 2008 on all new cars.  Only if
you bought a new car before then, or bought a used car that was made
before then might TPMS not be used.

Been a long time since I bought tires from just a tire-only store.  The
shops I use sell tires and do service, so they have the TPMS tools.  If
the battery is dead or the sensor went bad, the new one is likely a
generic that has standard scan codes instead of a manufacturer specific
unit with unique codes hence making later re-sync easier to do.
However, if the sensor has to get replaced (dead battery, damaged) then
the tire must be removed from the wheel.  No way to squeeze the sensor
package through the tiny hole for the air valve stem.  That incurs labor
along with rebalancing the wheel after putting in a new sensor and
putting the tire back on.  Then the tech has to sync the new sensor to
the car, so the car can connect to and read the sensor.  You can call
your favorite car shop or the dealer to get prices on sensor replace and
sync.  It won't be cheap per wheel.  Unlike replacing tires on an AWD
requires replacing all 4 tires at once, the TPMS sensors can be replaced
one at a time.

TPMS sensors aren't particularly accurate.  The recommended tire
pressure might be 32 PSI, but the sensor won't fire a warning until the
tire is rotating and pressure has dropped to 25 PSI.  When the tires
have worn and need replacement, that's a good time to replace all TPMS
sensors in all wheels.  TPMS is legally mandated to be present in new
cars sold since 2008.  There's nothing mandated that car owners must
replace defective or battery-dead sensors.  However, with or without
TPMS sensors, you should be checking your tire pressures regularly.  The
recommendation is every month, but I usually don't bother until 3 month
intervals (because I put very little miles on my cars), or whenever I'm
working on or around the car.  I have a digital guage which records the
peak air pressure (so I can remove it and then look at the reading) and
a small 2-gallon air compressor in the garage, so checking and inflating
are pretty easy on the car after sitting in the garage to cool down.
PSI also drops about 1 PSI for every 10 degree drop in temperature.  If
you drive your car everyday, don't be surprised if you lose 1.5 PSI
every month.

If you haven't disconnected the battery since the error codes went away,
an OBD tool should be able to check for TPMS error codes from history.
I got an OBD2 tool to plug into the OBD port on the car (under the dash
on the very left side near the hood release latch) which has an Android
app to read error codes, look at history, and other diagnostic data.
The OBD meter at the shop will likely be more complex, plus the shop
will likely have different models to read different year ranges of cars
and different cars to understand the data.  I'd have to do the same
online search to find out what are the codes for TPMS errors.

If the dash indicators went out, that was because you corrected the low
pressure by inflating the tires up to their recommended PSI (fronts are
often different than rears).  That indicates the battery is okay in the
TPMS sensor(s) inside the affected tires.  TPMS is still working.  I
wouldn't recommend deflating the tires down to 25 PSI and drive around
(to activate the sensors) to see if the light comes back on.  If you
keep the tires properly inflated, you won't see those indicators again.
However, you said it's a 2016 Subie.  If you haven't changed the tires
since buying it new then you're probably about due for new tires
depending on your daily average mileage.  Figure to replace the TPMS
sensors in all wheels when you get a new set of tires.  No point in
paying for a new set of tires plus installation and balancing while
keeping the sensors to only have to remove the tires to replace them a
year or two later.  

If you swap tire sets, like between winter and summer sets, you'll need
a TPMS tool to sync the different set of tires to the car.  As far as I
know, the car records only 1 code per tire position; i.e., you cannot
have a code set for winter and another code set for summer.