I need advice on choosing, installing & initializing new TPMS sensors in winter wheels and tires... I have many questions…

(Have also posted this question in the General topic area because I am new here & not sure which place is best… Administrator please accept my apology and delete whichever location is less appropriate if I have sinned here…)

The vehicle is a 2012 Chrysler 200 Limited with 18-inch wheels & the optional Electronic Vehicle Information Center (EVIC) which includes a full TPMS display (showing individual pressures for all tires) and individual TPMS transponders in the wheel wells.

I want to add winter tires on separate rims and would prefer to install TPMS transmitters in the new winter wheels so I will continue to have TPMS functionality in winter rather than an annoying TPMS failure light all winter long, but I have budgetary pressures… My winter rims would be basic steel rims, and I want to go down a size to 17-inch with a higher profile tire (same outside diameter as the OEM 18-inch summer tires). Also, since OEM TPMS Sensors are so expensive, I would prefer to use less expensive aftermarket sensors on the winter wheels, possibly the Schrader 33000 EZ-Sensor or another aftermarket option (ORO-TEK, ITM,) with an adjustable angle to make sure they fit in the steel rims OK. (I am finding a lot of conflicting info as to whether the OEM sensors in my stock “summer” alloys are EVO (#SE57772, 315MHZ) or Schrader (433 MHZ)… The most likely Mopar OEM part # is 68078861AA.)

Question 1: I notice in the AllData Tech Manual there is a Chrysler warning never to use TPMS sensors in non-OEM wheels, threatening “Undesirable system operation or sensor damage”… is this just someone covering their ass, or a warning I need to heed?

Question 2: will the sensors work OK in basic steel rims for the winter tires only? Is there anything about basic steel rims as compared with alloy wheels that is problematic for sensor fit or operation? Will the system work acceptably when I change from 18 to 17 inch wheels? I note that the base-model Chrysler 200 comes with 17-inch steel wheels and hubcaps, and has the same TPMS sensor part number, although I gather the factory initial programming of the central receiver/control module may be different… The centrifugal force on the sensor will be slightly different (about 6%) at any given speed, 17 vs 18-inch wheels, and the signal strength from sensors in solid steel wheels may be (uniformly for all 4 wheels) different than with the OEM alloys… am I going to have a problem? Reprogramming the control module every spring and fall on changeover is a deal-killer…

Question 3: As I understand it, my TPMS will automatically re-learn sensor IDs and positions during an appropriate driving cycle (at >15 or 25 mph for >10 minutes after >20 minutes with ignition off), hence my on-board system will automatically adapt to (on first use) the 4 new sensors and (every six months thereafter) changing between winter and summer wheel/sensor assemblies, without any scan tool programming etc, as long as I perform that re-learn driving cycle. However, I have read that certain (or perhaps all???) sensor types needing to be “programmed” or “activated” or “initialized” when new (out-of-the-box) before initial installation, in order to be able to communicate compatibly with the car’s receiver and transponders. Is this true? Does it apply for all sensors, including vehicle-specific (direct-fit, one-to-one) sensors, or only to the multi-application (multi-fit) sensors like Schrader EZ-sensor, Smart-Sensor and VDO Redi-sensor? Is this about customizing the sensor’s output/protocol to communicate with my specific vehicle, or simply “waking it up” (turning it on), or both? Which (if any) sensors will work (out of the box) without any special initialization requiring special tools or scanners? I have also read about a procedure to put a magnet near the sensors to activate them: is this applicable for my vehicle? Is it necessary? Is there risk of damaging the sensors? With shops in my area charging a minimum charge of at least 1 hour’s labour every time they pull out a scanner, there is a cost implication which may impact the economics of a cheaper sensor that needs programming versus a more expensive one that does not…

Question 4: As noted above, I am finding conflicting info as to whether my existing OEM sensors are 315 or 433 MHZ. Does anyone out there know for sure? Does it matter, i.e. can my vehicle’s central control module/receiver (and fender transponders) “hear” (and “speak”) both frequencies?

Question 5: Does anyone have experience doing this? Where I live (Ottawa Canada) everyone seems to just go without sensors in their winter rims, and live with the TPMS failure warning all winter… tire dealers routinely recommend it, but this seems a bit hokey as well as annoying (the continual warnings) to me… But I like to know the costs and risks before I start down a path…

Many thanks for any guidance.

Phipp