So here is the story. Red triangle, engine lights with a bunch of orange lights eg VSC abs. Scanned code P0a93 indicating inverter coolant pump problem. Replaced the pump, drained all coolant and added new. Bleeding system until solid coolant came out of the bleeding valve. Started the car fine with all warning lights off. However after driving for 1 min, VSC ABS and (!) lights on. Every time when starting the car, all warning lights off but came back on after short drive. Suspect the 12v battery problem, so replaced it. However those three lights still came back on after short driving. Btw the red brake light is always off. Scanned no code found. any ideas?
If you have the warning lights on and then scanned and found no trouble codes, it means that the scan tool that you are using is not good enough to scan all the dozen or more different systems in your Prius. You need a better scan tool. Read this thread: https://priuschat.com/index.php?posts/3246758
If it's the VSC ABS ((!)) lights, you don't have to depend on an iffy scan tool; you can just get the codes like this: Blink (a/k/a Flash) Codes – How to. | PriusChat
I had this with a naff scanner, with the same VCS ABS etc.codes. I bought the Autel MaxiAP 200 and all the error codes came through on it. Buy that one. It’s great for a gen 2, and cheap.
Blink codes are even cheaper. But a good scan tool can get codes from all the computers in the car, even the ones that don't do blink codes.
Update: this morning I powered on the car. As expected no lights came on. I started to drive and expected those 3 lights came back. Surprisingly no lights on whatsoever. Now it is evening I drove about 60 miles today. Still no lights came back on. I did nothing. Issue resolved by itself.
Update: I got Techstream working and found these codes -U0123 "Lost communication with yaw rate sensor module" -U0124 "Lost communication with lateral acceleration sensor module" -U0126 "Lost communication with steering angle sensor module" I have been driving 500 miles from last time all lights off. No lights is on the dashboard but Techstream still pick up the above 3 codes. Should I just erase them?
