Two problems and I wonder if they are related both are intermittent 2008 Prius 1) Once or twice a month the car will not start. I step on the brake and push start nothing no lights on dash. first time I thought dead 12V battery. Wait a minute step on brake and car starts sometimes I have to do this 3 or 4 times it has never not started and it has been doing this for 3 months now. 2) Try to lock car with handle get single beep, open close all doors no luck the car locks with the fob button or if I start the car & shut it off it will lock. this happens once or twice a week for the past year any suggestioins appreciated.
Hmm, might be two separate problems. If you leave the car in Ready and try to lock the doors, you will get the single beep. If the 12V battery is on its way out, sometimes the car won't shut down. How did you rule out the 12V battery as the potential problem? Have you ever had to jump start the car? I'm thinking about the FOB battery. Is it still the original? IIRC, they go for ~$2.50.
How did you rule out the 12V battery as the potential problem? Voltage 12.4 V nothing on and 12.0 V lights on Have you ever had to jump start the car? No I'm thinking about the FOB battery. Is it still the original? IIRC, they go for ~$2.50. red light blinks when button pressed
That value is considered anywhere from low to discharged. Battery Basics - How a Battery Works - Voltage http://www.aa1car.com/library/battery_runs_down.htm
12.0 Volts is not good. A low 12V battery caused all sorts of odd glitches on my 2008, all of which went away when I installed an Optima Yellowtop. I thought this was a great deal, and their customer service was excellent. 12 Volt (12v) Toyota Prius Auxilary Battery for 2004, 2005, 2006, 2007, 2008, 2009 and 2010 with installation kit
Jeff. If those are the voltages measured by the MFD in maintenance mode and after the cars has been sitting (off) for several hours or more then it's not necessarily that bad. Yes 12.4 is a little low but as there's some power drain while it's being measured then the open-circuit voltage would probably be about 12.5. Also assuming that "lights on" means normal headlights, and that you waited 10 to 20 seconds for the voltage to settle, then I'd say anything 12.0 or over is good.
One suggestion is that you replace the 12V battery and the fob battery. Another suggestion is that you keep the fob physically away from your cellphone. That might improve the responsiveness of the Smart system.
