I have a 2007 Highlander Hybrid that I bought as a Certified Pre-owned vehicle.
One the whole, I have been happy with the vehicle, except that as it crossed the 50k mile marker, the fuel economy took a 20% nose dive from about 25mpg, to 20 mpg. I have taken it back to the dealer and they have not found anything wrong with it.
…none-the-less, I suspect my battery pack has begun to fade in its effectiveness.
The dealer has a black-box, red-light/green light test that they do which tells them the battery is green, but they seem to not know, or not be able to tell me what the threshold is that there battery diagnostics tests. This leads me to believe that the battery pack is beginning to fade and just like other batteries, it is holding its charge less and less but not yet fully failing.
Is there any way to actually test the battery pack and compare its current effectiveness to that of the original or a replacement pack?
Is there any way to actually get some information out of Toyota, beyond, well, you car passes our diagnostic test?
The battery is still under warranty, so in the perfect world, Toyota would replace the pack and my car would be back to great.
But, maybe that isn’t really the problem, so I want to avoid the worst possible case, where I pay $5k for new batteries and that isn’t the problem.
Help me Tappet Brothers… you’re my only hope…