In another thread this was posted: This has some inconvenient and potentially costly implications for many owners. Possible safety considerations as well. For example; Q1. Does the SSB-AOB procedure have to be redone with a different calibration file if an owner has 17 inch "summer tires/wheels," but runs 15 inch tires/wheels with snow tires in the winter? Q2. If the SSB-AOB procedure has to be redone at each seasonal tire/wheel change, how much will it cost? (Simply registering new TPMS senders in a set of snow tires/wheels costs ~$60 at a dealer for a 10 minute operation.) Q3. What is the correct procedure should an owner install 18 or 19 inch after-market tires/wheels? Q4. What is the correct procedure should an owner install Gen II, 16 inch Touring tires/wheels on a Gen III car? Q5. Does mounting wider or more sticky tires on the Gen III OEM 15 or 17 inch rims require redoing the SSB-AOB procedure? Q6. Will changes to a cars suspension -- non-OEM shocks, springs, or sway bars -- affect or negate the combined regen/hadraulic brake system operation as established by SSB-AOB? While I do not own a 2010 Prius, similar questions would apply to me and the many other '04-'09 owners should a Gen II recall be in the future. Thanks
None of your questions makes any sense because people upgrade to aftermarket wheels or do snow tires/wheels seasonal change without altering the factory settings. Also, the fact that there are two different files disputes some people's argument here that the 17" wheel Prius isn't calibrated differently from the 15" wheel Prius.
When I had my car updated, they have to input things like yes or no for radar cruise control. Another question was 15" or 17" rims.
and the difference in programing (which is essentially changing timing delay) is going to be what??? the 5% difference due to wheel size differences? i think we are reading a bit too much into this
I'm not speculating as to answers. But I do think the questions are valid. With knowledge that there exists two different versions of calibration software for wheel size, I think questioning what this means to people that may change that wheel size throughout the year is valid. The answer may be that it means very little. Or the answer may be that Toyota has to officially state that they do NOT recommend making wheel size changes. But the questions are good.
true true, but we have absolutely NO VERIFICATION THAT THE SOFTWARE IS DIFFERENT period. what we have is different reference #'s only. in a database driven world, this is most likely needed to conform with database rules. i sincerely doubt there is major difference in the parameters
Per the SSC documentation, if the Tech is unclear, he is to follow what is on the B-pillar placard (i.e. what the vehicle was built as). Prius I-IV - 15", Prius V, 17".
I don't have verification nor am I in a position to verify but that would further suggest to me that there is a difference in software being applied to 15" or 17" wheels.
Hello from Japan, There are some rumors about this in Japan too. The most possible answer is... "The ABS is a part of S-VSC. The power steering motors between 15" Prius and 17" are different, therefore Toyota provides the different update software." It's just FYI, and it is not confirmed yet. Anyway, it looks Prius sends the vehicle information to the update tool, so the tool automatically selects the appropriate software to match the vehicle package. Ken@Japan
I suspect this is answer. Not what size wheels are currently on the car, but rather what size wheels did the car leave the factory with, since the cars built with 17" wheels (called the Prius V in the US) have slightly different parts (in addition to the wheels...).
The software flash is just a diversion to keep you occupied while the tech installs the *real* fix -- a zip tie around each brake to make it squeeze harder!
Felllow PRIUSchatters, I opened this thread on behalf of all members to be proactive in the matter of how SSB-AOB will be applied in cases of non-OEM or nonstandard use of OEM tires and wheels. I was thinking outside the narrow box of OEM equipped cars that remain essentially unchanged throughout their service lives. I was thinking of the many cars that have been or will be "moded" with new tires and/or wheels -- a relatively frequent thread topic in "normal" times. My intentions were and are to gain valid information. My intentions were not, and are not, to stir up trouble or cause confusion. I do not understand the intricate interplay of ABS, traction control, etc. I believe this is also true of most Prius owners driving either the Gen II or Gen III. The questions that I posed came rather quickly to mind, so I believe that they are representative of what many others may be wondering. I especially think that any owner who has or is contemplating changing tires or wheels would have the same questions. As to my driving a Gen II as opposed to a Gen III Prius, I note that in another thread Team Prius acknowleges that there is the possibility of a Gen II recall: My hope was and is that Team Prius will be the conduit through which my... no, make that our, questions will be quickly answered. Rokeby
Correct, namely different steering rack (and ratio), and a different power steering motor (brushless on 17" vs. brushed on 15") in the US. Thanks for digging that up Ken. The ECU being flashed controls standard braking, as well as ABS, TRAC, and VSC functions (which all leverage braking to some degree). While this doesn't control steering, the amount of steering force requested for VSC may differ.
The turning radius is different on the 17" V model. 36.0 ft on this version and the rest with 15" wheels are 34.2 ft. (Toyota Prius - 2010 Performance & Specifications) Mechanics at Toyota dealership also told me that they will have to upgrade the software in order for the system to recognize the correct mileage and speed. At the same time, I also read that 17" tires might rub the inside lining while turning because a different parts are involve in factory set 17" than the 15" wheels. I don't know if the latter part is true but for those who has upgraded, do spill your thoughts.
