My hybrid system warning light came on last night in my 2005 Prius with about 89,000 miles. The car may have run out of gas (I wasn't driving). This car will only take about 8.5 gallons when the fuel light starts flashing. I started it this morning, light was still on, only 2 bars on battery, my car usually runs near the green, and the gas engine stalled after about 30 seconds. The gas indicator was flashing, so I added a 1/2 gallon I had at the house, and unplugged the 12v for about 10 minutes to clear the system. Upon restarting, fuel light was still flashing, but no hybrid warning light. Drove a few miles, filled up with gas, and drove another mile. So my question, could running out of gas and driving a very short distance (light came on as my wife turned into our driveway), cause this warning light to come on? If so, will there be any lasting effects? Did unplugging the 12v battery clear the computer codes, or can I still get these read to learn more about what happened?
I believe the gen2 Prius will allow you to continue driving a distance on the HV battery once you have run out of fuel. I think this was designed to allow you to just pull over to the side of the road but unfortunately a lot of people try and see how far they can go and run the HV battery way too low, so low as to either need the car to go to a Toyota dealer to get it charged back into its 'happy zone' or so low as to have damaged it. Normally if your HV battery gets too low the engine switches on and charges it up. When you are out of gas the car thinks its put the engine on to charge up but doesn't as there is no fuel. I'm sure others will explain what you need to do next. If the car wasn't run too far on the HV battery you might be in luck. If they ran it until it completely died, then you might want to check how much remaining credit you have on your credit card!
Yes, running out of gas will cause those problems. I believe that's exactly what happened and for your other question, Yes, unhooking the 12V will clear all faults.
