Toyota dealership wants to install new main battery

Yes, those are the newer generation modules. You can tell by the shape of the plastic on top of the modules.

A new OEM battery from Toyota only has the battery pack section. This includes the module pack mounted to a new bottom plate, a new large cover, and the main cables on each side of the battery pack. If memory serves correctly, it also includes a new safety plug socket and cables that you need to install. The portion of the old battery with the electronics has to be transferred over to the new assembly. Then install the safety plug socket and cables. There're other items that also need to be transferred over. The cover for the electronics section will also be re-used from the old battery.

An unfortunate part about this is that quite often the problem with the battery can be corrosion in the ECU socket. A new battery does not solve that, only a replacement ecu will cure it.

 

A point of clarification, P0A80 is set by the battery ECU, not the ECM. The hybrid system is part of the powertrain and that is why the hybrid vehicle control ECU and the battery ECU set "P" (powertrain) codes.

PCM might feature in the short message of a DTC as these (P0xxx messages) are generic messages set by the SAE. Toyota does not have an ECU designated as a PCM and uses ECM to refer to the engine control module. To make things more confusing, the repair manual mentions the Hybrid Powertrain Control Module on multiple occasions which seems to be a long-form name for the hybrid vehicle control ECU (HV control ECU). So there's that.

 

You're not accurate enough. I don't trust the quality of your assertions that the dealer is doing whatever you insinuate. See attached picture