NEED HELP ASAP. Replaced water pump and still won’t start

You haven't said anything about codes except for the 261B before you did the pump replacement?

Your aux battery is low on charge, but not low enough to stop you from reading current codes to find out why your car is choosing not to go READY.



That's what would be my next step, before shotgunning parts. Generally when the car decides not to go READY it will be happy to tell you why. As you observed yourself, $250 would be quite a bit to spend on a shotgunning approach.

 

You have a current P0A0D. That hybrid system interlock will prevent the car from starting.

If the service plug on the traction battery was ever removed for any reason, not getting its handle completely reseated is a common P0A0D cause. If that's not it, there are other interlocks in the inverter wiring covers, but those are less commonly disturbed. And of course the wiring needs to be checked, if there's nothing amiss with the interlock contacts.

You still have a 'permanent' 261B code, but that will go away as soon as the car is operational again for long enough to figure out that the pump now works.

 

That voltage is very low. Wouldn't hurt to try a charging session, with a 3~4 amp smart charger, but probably replacement time.

 

The voltage is above Toyota's threshold for retrieving codes, and the P0A0D code shown in current status is the car saying right out loud, "hi! I am not going to start, because you have left the safety interlock circuit open, and I am programmed not to start then."

 

Look into 12 volt digital battery testers.

https://www.autoguide.com/top-10-best-car-battery-testers

I have a Solar BA5 (older model); see there's a Solar in the above list. Works well.

 

After doing that work, have you re-read the codes, and do you or do you not still have a current P0A0D?

The interlock circuit, which runs from the power management control ECU, through the inverter, back through the wiring harness, to the battery service plug, and to body ground from there, is a very simple electrical circuit. If the code about it has gone away, then that particular issue is resolved now. If the code about it is still present, there is still a discontinuity in it somewhere, and the P0A0D code will be present until you find and correct that. While there's nothing wrong with replacing your battery if you want to, as long as you have a way to keep the current one reasonably charged, that's as much as you need while tracking down where the interlock circuit is open.