I have a 2003 with 86K on the clock, I just put a refurbished HV Battery in it then, on the drive home the check engine light came on, its was the inverter coolant pump, replaced it with one from a parts car I have. After bleeding it it was fine for about 100 miles, then the red triangle came on so I drove it to the shop that swapped the HV Battery (my cheap code reader said no codes, their $10K unit came up with P3000 and sub-message "Battery control system malfunction" I left the garage and the red triangle went off and hasn't come back on in 40 miles> a little more info, the Hybrid display screen is very fuzzy and does not give any information except in the consumption mode where it always shows full bars and 99.9 MPG. Any thoughts on any of this?
I’m going to lean towards the battery ECU. Maybe when the HV battery was swapped, something was hooked up wrong. Just a guess, maybe some more senior members will pipe in.
P3000 is a generic code from the hybrid ECU. There will be subcodes leading you further down the path of diagnosis. There are a couple of ways to get those, but having an old laptop running Techstream software gets that information so you can research the cause. Keep us posted .
