I have a 2005 Prius with 170,000 miles and I replaced the main battery and the auxiliary battery last summer. Now every few weeks the red triangle followed by the problem coming onto the screen. I checked them with a code reader and it says no codes found. I reset it and it’s good to go for a few more weeks then same problem again?? Now it the past month I have also noticed that my miles per gallon has dropped from 45-42 down to 37-38?? Anyone experienced the same problem or know of a solution?? ThAnksin advance!
Welcome to PriusChat!! Tell us more about this HV battery replacement, was it a brand new Toyota OEM HV battery or something else? Even though you can't read them, there are DTC codes. Best to find out what the problem is and fix it. You need a hybrid compatible code reader, try borrowing a better reader from another auto parts store. If you have a laptop/computer you should purchase a mini-vci cable ($20) w/ techstream. And at a minimum should grab a bluetooth OBD2 adapter for $2+ and a phone app. Most likely that HV battery is failing, continued resetting and driving will only make matters worse (generally speaking).
When the car is ready, open the hood and check the inverter coolant reservoir, see if you see movement in the fluid. I suspect your inverter pump has failed. When you drive short distances, everything is normal. But when you go farther, the car gets too hot and triangle appears. Will go back to normal when the car cools again. Your AC will probably not work when this triangle appears, as a overheating condition will shut down the compressor
Today I checked the inverted coolant pump and it’s working as it should. I rechecked the codes and it still says no codes found. I reset the error and The car ran just like normal. After it was parked for about 5min I started it up and now I have zero dash lights? Could this be the starting battery dropping below 12 volts??
You have more than 1 problem. 1. You should check you oil level, that might be the cause of the triangle 2. No lights in the dash means you have a failed combination meter. You can order a rebuilt part for $150, it's a common 1 time failure on these cars
