Hello, I bought a toyota prius gen3 "2010-2015" with the odometer stuck at 85645km. I suspect the odometer was roll back. Because, I see on the service book, that in 2017, the mileage was 355000km. It is after export in my country (Senegal) that the mileage has been intentionally decreased. Now the odometer is blocked and the buttons "DISPLAY and TRIP" do not work too. So I can not know the maintenance periods for oil change. Question 1: Is it possible to reset the original mileage (85k - "355k) without disassembling the combination meter (only whit obd2 software)? Question 2: Is it necessary to reprogram the ecu if I have to replace the combo? Or is it enough just to replace the older combo by the new one? Combination meter part number: 83800-47390-4 Vehicle references: toyota prius gen3 ZVW30L-AHXEBW 2009 Europe market. Please help me because there is not enough qualified service for hybrid vehicles. Thank you in advance and excuz for my english. Posted via the PriusChat mobile app.
The mileage is not automatically reset by replacing the combination meter. It is reset with Techstream. Not having done it before, I don't know if it requires a connection to Toyota's master computer.
You have asked about a Gen 3 car in a Gen 2 forum. We do not necessarily know the answers to your questions as we may not have the required overlap in knowledge. You should post this in the Gen 3 forums to get the best most reliable information.
The mileage can clearly be reset by direct writing to the memory chip on the combination board. Since you can order a replacement board with the same mileage indication as the original board, I have to assume that it is done via software. That said, I've never heard of anyone using Techstream to accomplish it. There is probably a Techstream module that is only available within Toyota, not including dealers.
I used to know an engineer who serviced Gen2 combination boards. He showed me a board with solder points labeled with the memory chip functions. He said that it was rather easy to infer the memory setup by watching how it changed as he clocked the speed input. The memory chip can be programmed in-circuit - it doesn't have to be removed. While writing to the memory chip could be done with access to the back of the board, figuring it out would require removing the display unit to see the top of the chip. Desoldering the 75 or so connections without destroying anything is not something I'd like to attempt...
That's my impression too. And when you buy a replacement meter, the seller typically has a bunch, with various miles, and you're supposed to tell him what your mileage is, and he sends you one that's "close". A lot of loopholes in that process though, in particular how honest the buyer is.
That's what Matt at Texas Hybrids said he had one that was 10,000 miles lower than my mileage. I said send it lol....
The technology for modifying an odometer has changed from earlier years, but it's still possible. Instead of using a mechanical pick to jump a wheel, now it takes an electronic device to reset a memory chip. Ethics, and car salesmen, haven't changed all that much with the introduction of electronic engine management or speedometers.
Thank u guys, i finaly ordered a new combo and replaced the old one. The mileage work now very well. But the steering wheel button did not work. So i ordered a new CLOCKSPRING, when i replace it, the touchtracer and switch button on the steering wheel work very well. I do it by myself. "Priuschat is great, God bless all" Posted via the PriusChat mobile app.
The law may forbid intentionally putting in an easy or non-intrusive documented way to do it. But a law can't abolish the technical reality that hackers or hobbyists with a bit of technical knowledge and willing to dig in with intrusive methods, may still be able to find a way.
