First, I had trouble with the front camera, I was always getting a message telling me to clean the camera. I called a reputable local Toyota dealer to ask for advices and they suggested it could be caused by a bad 12 volts battery. But then, the trouble solved itself when I parked the car under the sun. It removed the layer of frost on the windshield right in front of the camera. Anyway, I did use a multimeter to measure battery voltage. I had 12.28 volts when the car is off and 14 volts when it's in ready mode. Is 12.28 too low for an hybrid? I know it could cause trouble if I had a normal car but then, the Prius rely on its 200 volts battery to start the engine. I'm wondering if all the electronics and computers start to suffer when the 12 volts battery drop below 12.4 volts?
The short answer is NO. I've started my gen4 when my battery was less than 11.75VDC without issues. The Toyota mechanic is correct, low voltage can cause phantom errors to pop up, but usually closer to 10.75VDC or lower. Once the car is in 'Ready mode'; the DC-DC converter takes over and your basically working off the large traction battery. Has your windscreen been replaced? Possibly not recalibrated properly??? You should probably check the electrolyte levels in your 12V battery. Down here in the states, most auto parts stores will do a free battery test for you. Hope this helps.....
The windshield was replaced three years ago but, it was recalibrated properly and I didn't have any problem until last week. Then, I had a nice surprise this morning... I parked the car facing the sun and the frost between the windshield and the camera cleared itself. Then, boom the camera is working again.
