Prius 2004 - Error codes

P3011. This error indicates a malfunction in the pair of modules numbered 1. The error is generated by the difference in voltage between adjacent pairs. As you understand, the difference can be higher or lower.
If there is an abnormal internal resistance or electromotive voltage in the battery blocks, the battery ECU determines that a malfunction has occurred.

The engine system has errors in the catalyst and in the incorrectly functioning fuel mixture formation in the engine.
When the air–fuel ratio feedback is stable after warming up the engine, fuel trim is considerably in error on the RICH side (2 trip detection logic)
There are errors in the hybrid part as well.

First, it is necessary to deal with errors in the high-voltage battery.

 

So, the various ecu's have a memory buffer that "records" some data as the car operates. If a fault triggers a code, then the ecu saves a snapshot of that data for the freezeframe.

The thing is, there can be some time lag between the fault happening, the ecu figuring that out, and saving the data. Add in the update speed between frames of data, and you might not see the actual "fraction of a second" point in time when the fault occurred.

You should see the general operating conditions.


If you use your scantool to monitor battery block voltages while driving, you should see what's going on (Dr Prius app is a handy option to view live battery data).
Posted via the PriusChat mobile app.

 

That pack is way out of balance, with 0.8 volt difference between blocks 1 and 7. If you can find somebody nearby with the tools to rebalance it in the vehicle, perhaps do that before you start swapping modules.

What is the history of this pack, is it a rebuilt one? Does it have a warranty? If so, use it.