hey guys somebody can help me I have a 2004 prius with p3000 sub 123 this is the only code. This happen after a replace a cell. Now I check every cell all of them are around 8 V. p3000 subcode 123 is abnormal signal from the battery
Check the wiring harness within the traction battery to ensure it is in good condition. If it is, then the traction battery ECU likely needs to be replaced.
I am having this same code P3000-123. Wiring harness appears to be in good condition. Traction battery ECU is actually in the battery itself (not the one under the dash) correct?
Yes, if looking towards the front of the vehicle the HV battery ecu is on the left side of the battery pack. Check the ECU connector and socket.
The P3000 code, IIRC, is one from the Hybrid Vehicle ECU that means it received a signal that there are codes in the Battery ECU. There would be more information to go on if you had access to a scan tool that would report the original codes from the Battery ECU also.
For the battery ECU, like any other ECU in the car, reporting a trouble code virtually never has anything to do with the ECU "going bad". It is simply the ECU doing its job to tell you something about the car that will be useful for you to know.
Corrosion is common. Given the vehicles age and the humid location, you should look for corrosion in the likely places. If you find that the ECU pins are corroded, you may want to remove the ECU cover and inspect the circuit board as well. You may notice how the corrosion on the ECU pins cause them to break off inside the voltage sense harness connector. Many of your local dealers sell a new voltage sense harness for around 55 usd.
If you have only one code P3000 check the upper right pin on the ECU in the picture above. Is probably corroded. I think this is the error reporting pin. You can try taking an emery board and sanding these pins. It sometimes fixes the problem for a month or a year depending on damage.
If you have a reader showing you only a P3000, you're not getting all the information you could be. P3000 is a code in the HV ECU up front in the car, not even the same ECU as the one that has the information you need. The HV ECU sets P3000 only to tell you that there are codes in the battery ECU that you should be reading. If you don't see those codes as well as the P3000, you might have a reader that can't show you the battery ECU codes. By getting those read with a reader that can, you'll get the best head start on solving your issue. Sometimes those codes will be about implausible voltage readings from some of the battery blocks; if those are the codes you have, then that orange connector shown above is a usual suspect. But if those aren't the codes you have, it will be more productive to focus on the codes you do have and what they mean.
