Ok guys, So got the red triangle, vsc, engine light on my daughters 2007 Prius. The battery display only would show 1-2 purple bars. After reading a few things here, I took the battery pack out and checked the cells with my voltmeter. Because of time constraints, I just changed out the battery cells that showed below 7.0 V, which was 2 cells. I did not perform the charge/ discharge/ capacity test. I placed the battery pack in place. The car started up, display looked good hitting green at one point. However as I drove down the road, heard a clicking noise from the back, the battery pack shut off, alarm lights lit up my dash as before, and the car went into engine only mode, higher RPM, etc. I pulled over to the side of the road turned the car off and immediately turned the car back on and it started as normal- normal power, and appeared to have normal battery function. I drove down the road another 10-15 minutes and the same thing happened again. Battery appeared to kick off, higher RPM, no regular power. I pulled over to the side of the road, cut the car off and again, immediately started it back up and it ran normal for another 10-15 minutes or so and the process repeated itself. I am planning to take it to someone who can read the car codes but I was wondering if anyone here has any ideas.
welcome! not sure what the clicking noise is. relay? have you cleaned the fan? might be overheating and going into protection mode. one things for sure, it's time to do a proper rebuild or move on
That’s a good idea. Get the codes read and get back to us. My guess is you messed something up in your hurry to finish. Hopefully its something small and you didn’t do any damage.
The clicking noise is the main power relay that connects the battery to the car. Those are the relays you saw inside the battery box. The system detected an issue with the battery so it disconnected it from the car. Then your in limp mode. It threw a code when that happened you need to get that code harvested. My guess is ground fault. How bad was all the bussbars and interconnect corroded? All corrosion must be removed and cleaned up or your just wasting you time. There's hundreds of posts about this scenario.
You also did not mention using a small torque wrench to tighten the terminals properly. It is time to order @2k1Toaster kit of new cells from the link in my signature.
Code was received.: P3021- Block 11 becomes weak. Yeah, I actually went through and removed and cleaned all bus bars and nuts. I just ordered new ones to replace old ones when I pull it out again.
That’s why every module needs to be load tested and it’s discharge rate monitored. You initially just did a Craig’s list whack a mole repair.
