OK, so I've got an 07 with 200k on it, its my third prius and the first time I've ever had a problem except a wheel bearing once. But this car is making up for all the good luck I've had. So the traction control light is coming on and off and its mostly happening when I'm on the highway driving around 65 mph plus. and when it comes on the hybrid battery meter drops down to one bar real fast, and stays at one bar or zero bars for the whole time I'm cruising on the highway. Now when i leave the highway the color on the battery meter goes to green and charges the battery right up. now the car runs fine and charges the battery like it should when driving around town and at lower speeds. it only seems to act up on highway. the car also feels like it has resistance on the wheels when i let off the gas pedal, like the brakes are sticking or maybe a wheel bearing issue, but my mechanic says no and also when on highway and it goes to zero battery and the traction light is on the gas motor doesn't seem to be coming on. anybody have any ideas what the issue is? thanks.
What you are describing is what happened to our 2007 when we had different size tires on the front versus the back. Matching all 4 tires solved the problem. Apparently, this can even happen if the tires are the same size but one pair is severely worn versus the other pair. I realized what the problem was pretty quickly, since I had just put 2 new tires on the back wheels, so I never got around to trying to read any codes. I just returned to the tire store and bought another 2 tires of the same size for the front and that solved the problem. There might be other reasons a traction control light can come on intermittently, but I believe the lack of charging for the HV battery is to be expected when the traction control light is on.
The behavior of the traction light appearing above a certain speed is consistent with a difference in tire circumference. That leads to a difference in wheel speeds proportional to the speed of the car. Drive fast enough, and the difference becomes big enough to trigger the light. In Techstream there is an ABS History utility that will show you everything that was happening the most recent four times the ABS activated or the traction light came on.
A simple way is to get an OBDII bluetooth enabled adapter (that plugs into the diagnostic port under your dash) and then run an app such as Dr Prius: Hybrid battery diagnostic and repair tool for Toyota and Lexus It will tell you the health of your battery and give you a readout of any diagnostic codes. Another is to run Techstream which gives lots of info about the entire vehicle but is somewhat more complicated to set up. I don't have experience with that, others can tell you more about it.
It sounds like the Traction Control is activating when it shouldn't. If you have the DrPrius app with a compatible OBD2 adapter you could temporarily disable T/C and see if it stops acting up. If so then inspecting tire sizes (diameters) would be the next step. Posted via the PriusChat mobile app.
If you have access to an old Windows laptop to run Techstream on, or you have access to any friend or shop who has it, you can ask the traction control "hey, what made you activate, the last four times you did?" and it will tell you.
Yup, that will be in the history report of the last four TRAC activations, along with the throttle position, steering angle, yaw rate, and longitudinal and lateral g forces.