Help! 2005 Warning lights on, won’t start

What kind of code reader are you using? I'm under the impression that the generic ones you buy at any autoparts store don't show the hybrid codes, which could be your problem.

When the hybrid battery is worked on it's usually because one module went bad. There are 27 other modules just as old and as the one that went bad that are also on their last leg.

 

We need the DTC and sub code numbers to really provide you with much two-dimensional troubleshooting. As Isaac, indicates your code reader needs to be compatible with your Prius.

 

When you say you bought a new battery, are you talking about the 12v battery that is installed in the rear right corner of the trunk area, or the big hybrid battery located behind the rear seat?

When you say the car completely died, did all the lights and warning lamps turn off, or did it just lose all 'driving' power?

If you replaced the 12v battery, you most likely reset all the codes and temporarily cleared the condition that caused the codes. Disconnecting the 12v battery will return all the car computers to default condition. After restoring 12v power with the new battery, perhaps it merely took about an hour for the initial 'fault' condition to reappear.

Between the warning lights appearing, and the car completely dying, did you do anything? Did you pull over to the side of the road and turn the car off? Then try to restart it? and then it wouldn't work? If that's the case, then you have a P0AA6 fault. This would be reset by disconnecting the battery, but would likely come back soon after installing a new one. When it triggers, it will let you continue driving the car, but once you turn the car off, it will not allow the car to go into 'ready' condition again. (unless you disconnect the battery again to reset it, or reset it with a scan tool.

Unfortunately, we're all kind of guessing until you're able to get an accurate DTC reading.

Where in the 'USA' are you?

 

@peachy_

If that reader is actually displaying the correct code, a P1121 is for failure of the coolant flow control valve. You can read about it in the attached file.

Now, that being said, a true P1121 doesn't typically cripple the car and it's not an uncommon code for people to keep driving with for a long, long time before doing anything about it. It's very likely you have other codes that are not being detected by that Actron code reader. I don't think it's Prius friendly.