Dr. Prius Question

I have gone through the process of reconditioning my HV battery. A very lengthy process with results yet to be determined. I was wondering how good the battery was and I had read much about the Dr. Prius app … so I installed it. Block number 1 is frequently shown as very short column in light green while the other blocks are bouncing around in brighter or darker green. This happens when I first start the car. After the battery warms up Block 1 will change to other shades of green and bounces around with the others although maybe not as much. It might be that this happens when the battery is cold but as it warms up the problem goes diminishes or goes away. I did a road test of about 15 minutes where the regenerative braking (through acceleration/deceleration) charged the battery up to over 75%. I drove the last 1.6 miles on battery only and still had over 50% remaining. Last night I went to drive the car and my HV warning light came on. I think the voltage of Block 1 was 1 volt less than the others. I disconnected the battery for 5 minutes and the warning disappeared. My question are: What do the different colors mean? What does the height of the column mean? What does it mean that block one is a short light green column while the others are bouncing around with darker shades of green?

 

I think I may have found the problem. Corrosion is frequently mentioned as a problem regarding HV battery failure. Viewing the pins of the voltage sensor and the cable that connects to it is rather difficult. It appears as if there is some blue/green in the female pins of the connector at the end of the cable and a male pin of the voltage sensor seems to have severe discoloration. Not blue/green but more of a brown. Specifically the red wire that is associated with Block 1 connects to this pin. Is there any chance that this can be salvaged through a chemical application. The only way that I have seen to purchase the parts is on eBay. Any suggestion would be greatly appreciated. Sorry that I did not get the full connector in the picture …. Thanks in advance for the help.

 

Thank you for the response. I have read that the corrosion creeps through the wires. Do you have any suggestions on the fluid one might use to help clean the ECU? Is there any way to clean the female sockets that are at the end of the wire sensor harness? Are there any other precautions one might use to address the sensor wires? And lastly if I had to replace the ECU and the sensor wires, where would I shop for those?

 

Do you know of a video or some instructions or a brief explanation on accessing the ECU? It looks like the battery modules must be removed and (from the back of the car looking forward) the black relay holding unit has three nuts that must be removed and then there are 4 screws that allow the ECU to be taken apart. Part of the case of the ECU seems to be permanently attached to the metal frame.

 

To get to the voltage sensor you must remove the black block between the fan and the voltage sensor. That requires removing 3 nuts . The voltage sensor is held on buy two nuts, The voltage sensor comes apart with 4 screws. I cleaned the discolored pin and the car seems to be doing much better. The problem remains in that there is a slight bit of corrosion on the computer board and the metal leading from the socket holding the pins to the computer board. Even if the problem is gone, I think it will be temporary.