I’ve always referred to Prius chat over the years and this is my first ever question. I had the thermometer replaced due to high coolant temperature warning. After the repair and driving a couple miles the Hybrid System warning light came on. The repair shop (not dealer) said when unplugged the AC from the hybrid battery the warning light went off so I need a new AC compressor. I never had any issues or heard any noise from my AC prior. I’m very skeptical of this just happened out of the blue. Thanks for any info or advice.
Drive around a few days unplugged . Then in about 4 days plug the orange plug into compressor jump in car turn on air Lo temp hi fan. And button in. Is cold air coming . Lights? Read codes . Had this exact issue on my 13 persona the hybrid battery failing was causing my issue. SC would dangerously drain HV battery then code .change battery issue gone . While unplugged I was able to drive around with my dying battery for another 5 or 6 weeks anytime I plugged it up while the system stayed the same it would code almost immediately and I could see my HV display dropping drastically unplug it everything seemed to work fine. A quick look at the HV battery and we knew what the problem was.
The AC was running cold? I’d ditch those guys, splurge for a dealership check of codes and their opinion. just a heads up: a gen 3 with 150k miles, presumably EGR system never cleaned (optimum is at least every 50k), you’re likely close to engine head gasket failure. there’s some links in my signature related to both EGR and head gasket (on a phone turn it landscape to see signatures). Dealership is the last place you want to go for EGR, and likely also for head gasket, if and when. Disclosing what US city you’re in (or near) will help responders.
The engine overheating could be the engine water pump starting to go bad. Keep a close watch on the engine coolant level. Did the repair shop scan your car for trouble codes? Did they tell you what the trouble codes were? If not, this is the first thing that needs to be done. You said the Hybrid System warning light came on. Which light exactly came on. The red triangle or one of the other warning lights? Look in the owners manual for all the warning lights. Did the repair shop reconnect the AC compressor wire? Did the warning light come back on? Do not agree to any repair on your car until you have all the trouble codes.
