I have an 05 Prius that has 200,000 miles. Recently had the hybrid battery checked and replaced 2 cells. Replaced the starting battery. Replaced the coolant control valve assembly. Drove it home after the cells were replaced (about 35 miles) without issues. Now the check engine, triangle of death and VSC lights are all on. The issue is that when I have the codes read at 2 different auto parts stores, no codes are coming up. It was still driving fine, and the lights usually would only come on after starting it. Had not had any lights coming on while driving it, until today when I took it on the highway. The lights then came back on and the hybrid cooling fan was blasting. Any ideas?
you need tech stream to read the codes, but in all likelihood, replacing modules is not the answer to your problem. it often requires much more work than that.
Welcome to PriusChat!! If the warning lights came on today while driving, then you should try scanning it today, don't reset the lights without first recording the codes. Knowing the OBD2 codes (DTCs) can help in diagnosing the vehicle, see if a local repair shop can scan it for free, then post the codes here. Try scanning at all of the available parts stores, as each location is different and one may actually have a hybrid compatible OBD2 reader. DIY: Many will use a "mini-vci" cable (20usd) and techstream (toyota dealer technician software) on a windows device like a laptop, others may use a OBD2 bluetooth adapter and an App like Dr Prius or Hybrid Assistant on a phone. If using iOS, you may be able to emulate. At a minimum, it sounds like you're having an issue with the HV battery, best to use that 30 feet or 30 seconds warranty before it expires.