I have a 2004 prius, while I was driving around 20kmph then on dashboard it show Red Triangle + Check engine + ( (!) ) Brake system + Hybrid system on MDF and Hybrid Fan starting to kick hard that I can clearly hear while listening to music. Also the acceleration is reduced and I pulled over and use my OBD2 Bluetooth to check the code and found P0128 which supposed to be Thermostat. After that I got a thermostat replaced and clean the code then the car driving normally for the last 2 days. Later on it show the same thing ( Red Triangle + Check engine + ( (!) ) Brake system + Hybrid system on MDF ) but this time there is no code found while all those symbols light up. What should caused the problem? *Note: Airbag lights fixed already. Thanks for sharing. Posted via the PriusChat mobile app.
There's probably sub-codes that your code reader isn't seeing... the Dr. Prius app for your phone might be of use for that... You have to buy a bluetooth adapter: Hybrid battery diagnostic and repair tool for Toyota and Lexus The other option is the Toyota Techstream reader and computer software. Once you know the error codes this website will tell you how to fix. Also a quick easy fix is to disconnect 12v battery for 5 minutes and let the light and codes clear. They might come back, they might not. Also make sure you have a healthy 12v battery.
Thanks for the reply. I have checked the high voltage battery and they all reading in respectable voltage. Thanks Posted via the PriusChat mobile app.
I can clear code thought Bluetooth OBD 2 Scanner and car works fine again. But come up again and again. 12v battery and HV battery also and still the problem. I did a lot of research with this and seems like my inverter pump is bad so I checked it and inside inverter coolant resevior, there's no turbulence or any wave at all then I touched the actual pump but it seems to works fine. But why isn't turbulence there? Thanks. Posted via the PriusChat mobile app.
Thanks. I tested, the pump is fine but don't know why there is no turbulence or wave. I use LAUNCH scan tool to find codes, and it shows that I have a problem with HV battery in block 6. I'm going to replace those two cells and let see if it trips the code again. Sorry for my English. Thanks for sharing. Posted via the PriusChat mobile app.
Based on photos #1 and #3 in your original post, I'll bet the HV pack has a weak module or two. If the HV battery charge meter goes from: top > bottom > top in under say 5 miles of driving, it's in the HV pack. Additionally, the HSD cooling pump may be turning, that does NOT mean it is pumping. Debris can get into the system and damage the pump impeller, if that happens eventually the flow stops even if the pump runs.
i don't know how to balance them but i measure all cells include newer and then all giving from 7.4v to 7.8v. it seems fine for now. let see if another module fails after it. Thanks.
Thanks for your information. I got mine fixed by replaced block 6 because of its weakness. now car runs fine. let see if other modules will failed after that. and i still keep an eyes on Inverter pump also. Thanks.