Hello - I've read these forums for years, but never registered because I never had the need to post...until now. We own a 2004 Prius with 149,408 miles. We replaced the 12v battery in 2009. Just the other day, it seems that pretty much ever warning light came on, including the master. Any ideas on how to troubleshoot? We are unsure if it is safe to drive it (or if it will break down). Any assistance is very much appreciated. I tried including links, but since I just registered, it will not let me.
The first thing to check will be your 12V battery voltage. A low 12V battery will trigger all kinds of alarms. Check the 12V battery at the battery terminals if possible or at the jump post under the fuse panel in the engine compartment. If it is below about 12.2V after sitting for at least an hour then chances are that you need a new battery. Turn the headlights on and if the voltage drops well below 12V this will help confirm the battery. If the 12V battery is not low then you will need to get the DTC's pulled and post on here so others can help diagnose.
You need to give us more information. Was this at startup, or during the middle of a trip? Did you ever get a letter from Toyota telling you that the inverter cooling pump is subject to a special service campaign for free replacement, and have you had it replaced? Do you hear the HV battery fan running in the back seat area? A good option for independent service in your area is Josh Mellor at Mellor's Automotive in West Melbourne.
Thank you for the quick replies! My husband is going to check the 12V shortly and I'll report back. The lights came on in the middle of a trip, about a mile from our house (the photos were taken right after the car was parked in the driveway). The only letter from Toyota we have is for the hybrid water pump replacement (that we just got) and it has not been changed yet, but we were planning to take it in sometime in the next week. While I'm dying to get the Prius V, I am not dying for the payment, so we are in "preserve" mode if at all possible!
Hmmm...we have no current recalls on the car (that we have received notification for); just the limited service campaign for the water pump.
95% likely that it is your inverter cooling pump aka hybrid water pump. They are one in the same. It is somewhat of a miracle that it lasted this long. You can self-diagnose by watching the following video:
Ok...there is definitely turbulence in the water pump reservoir. Battery was at 12.6 and then 11.5 with the lights on. Any other ideas?
If you hear the fan running in the back seat, it is the hybrid battery. Otherwise, there's no way to tell without getting the codes read.