After Gasket repair, got "Check Hybrid System..." error

It is doubtful the AC works if it won't go to Ready.

 

Did you disconnect any wires from the inverter?

One reason for the P0A0D code is that the orange safety disconnect plug for the hybrid battery was not inserted correctly. Did you do all three steps when putting that plug back in?
View attachment 272365

 

Check the service plug, remove and reinstall it.
Check all the connections, again, even ones your think you didn't disconnect.
Was everything working before hand? I can't remember.

It's either the service plug not installed correctly, or a loose or bad connector.

 

???????

I did not ask you any questions about the EGR. I asked if any wires were disconnected from the inverter when you worked on replacing the head gasket.

I also asked about the orange safety plug. Did you do step #3, which is to slide the handle. The diagram I posted is for a Gen 2 Prius. The Gen 3 is very similar.

 

The safety interlock circuit that P0A0D refers to includes the pair of small contacts on the orange service plug (the ones that only mate when the handle is slid sideways in the last step) and also includes contacts beneath some of the inverter covers. If any of those covers were off, double-check those too. There are some good threads here about P0A0D troubleshooting.

 

I read this again and now understand that you disconnected the large orange cable from the inverter. Did you disconnect any of the low voltage wires from the inverter?

 

Sure, but there's a trap I often see people falling into here. While waiting for the scanner to arrive, it feels important to be doing something. But other than a quick check of the charge on the 12-volt and a reasonable check for cable connections you might have disturbed in the work that you did, you can end up "systematically narrowing down" a long list of things you have guessed belong on the list. (And sometimes, in doing all that, you can introduce new problems.)

While waiting for a scan tool to arrive, it can be worthwhile to do the thing that feels counter to the urgency of working on your car, and just look at whatever other things are on your plate (dishes? lawn mowing? bills?), and when the tool does arrive the car may end up fixed just as quickly when you are able to see what problem it is telling you about, and you haven't created any new ones.

 

Since it's showing the error code for the inverter no producing the correct voltage,
perhaps that cable you removed is not on properly????

 

One of the biggest traps in troubleshooting is assuming steps that passed your initial test or inspection are correct and never retracing your steps. It leads to an ultimate frustration and a sense of nowhere to go further.

The ac compressor runs on high voltage and you have none until Ready is achieved.

Doing a major repair without a good Techstream scanner or equivalent is really a recipe for frustration.

 

Waiting on the video