My Gen 2 had been flashing Check Engine yellow light for a couple weeks. Now, it won't start and Check Engine yellow light comes on when key is inserted. I haven't checked for any codes yet but thought I would ask if anyone has any ideas. I thought maybe an oil change was due.
A few more details about what is happening when you try to start the car are needed. When you say it won't start, do you mean it won't go to Ready mode? Are there no other lights that appear on the dashboard when you press the Power button, with your foot on the brake? If your 12V battery is sufficiently charged, pressing the Power button will normally instruct the HV battery to attempt to start the Internal Combustion Engine after a few seconds, unless your HV battery has been depleted to the point where it can no longer crank the ICE. As this is happening, you should hear a sound similar to an idling ICE for a few seconds as the cranking occurs. Do you hear nothing when pressing the Power button with your foot on the brake? Hopefully you haven't tried to start the car unsuccessfully so many times that the HV battery is now depleted and is incapable of cranking the ICE. If that is not the case, my best guess would be that your 12V is depleted to the point where it doesn't have enough power to close the relays that connect to the HV battery. I believe your first task should be to measure the voltage of the 12V at the front jump points under the hood with a multi-meter. You should see that voltage as 12.0 V or better to be sure the 12V is not what is preventing your car from starting. If your car has passed 5k miles since the oil was last changed, and the person changing your oil remembered to set the meter that keeps track of oil changes, the Maintenance Required light would now stay lit on your dashboard, whenever the car is in Ready mode. Miles travelled since the last oil change does not have any effect on the Check Engine light.
Will check codes, gas cap, and 12v. The Ready light does not come on so the only light is the yellow check engine.
I measured voltage at the fuse box jump point and that was 3.6v. There were no symptoms before this so guessing something was left on when I last parked it.
I jumped the Prius and started it right up. Voltage is measuring 13.6 even with the ICE off but with the car ON. I'm guessing this is normal, although not for a conventionally powered car. The battery is an 84 month Toyota battery so I may check into that but this also could have been just a current drain issue...not sure yet.
On a related subject, I found some water in the 12V battery compartment, although it's not deep enough to reach the battery at this time. Any ideas on the source of this? It's been rainy recently so wondering where this would likely be entering.
The ONLY thing that causes a flashing cel is a serious misfire. Typically due to a failing sparkplug, coil or injector. Most commonly a failed/failing sparkplug.
How often do you drive the car? Do you have any aftermarket equipment installed that may be draining it? If it's been a week or 2 since you had driven it last, it's quite possible that it could have drained on its own even without unusual events, such as a door being left open, or malfunctioning aftermarket equipment. If the car is not driven at least every couple of days, and you don't have the 12V on a battery maintenance charger, it's unlikely that it would last a full 7 years, although I guess Toyota would still be responsible for giving you credit towards a new one on a pro-rated basis. The battery on our Gen 2 is now 5 years old, and we keep it on a battery maintainer because we expect it is getting near the end of its life. Also, the best policy is to lock the car whenever it is parked, since the car's alarm will alert you to a door being ajar, if that is the case when you try to lock it. The most common source of water leaks on these cars is the seams (covered with a strip of rubber) between the car's roof and the rest of its body. Another place water may enter is through the seals surrounding the hatch or through the taillights.
THIS. To be more specific, the ECM flashes the CEL when it calculates that the amount of unburned fuel resulting from the misfire will be enough to damage the catalytic converter.
