I don't have enough detailed knowledge of the highlander to provide any DIY advice for repair or speculate on the problem. I've been a member of this forum for a few years and have not heard of any similar issues. I would take it to a toyota dealership for diagnosis & repair.

 

Original 12V battery? That would be the first thing I would check...

 

Your car has a five year, 60,000 mile powertrain warranty- and the hybrid battery is warrantied for even longer.

Take it to the dealer and ask them to diagnose the issue.

 

I will be taking to toyota for my next oil change to get a full tune up.

Just another thought- it is generally not a great idea to ever approach a dealership and ask for a "tune up". Instead, read the maintenance guide that comes with the vehicle and stick to what's recommended by Toyota based on years/miles. If someone asks for a "tune up" on a modern vehicle, many dealers will use that as an excuse to pile on a bunch of unnecessary stuff.

Ask them to perform the 50,000 mile service (or the 55,000 mile service if that's the mileage) and mention the specific items that are to be addressed based on the maintenance guide- and ask them to investigate the issue that you had.

 

Agreed, a "tune-up" is like giving a blank signed check to the dealership. Rip-off time!

 

I also had problem from when the car was bought new with the 12V battery. I've seen the message regarding air conditioning being temporarily stopped because of overcurrent. The problem was hidden by the fact that when the system starts, the converter takes power from the hybrid battery to refill the 12V battery. But if the 12V battery is not good enough to get to the point where the converter starts, then you get ALL SORTS of error message, and the vehicle does not start (ie it won't move).

I mean, with older vehicle with a starter, you would hear the starter trying to turn the engine and dying out of power. That would warn you of what's the problem. This does not happen with the highlander because it is the hybrid battery that starts the engine.

You can check the voltage on the 12V battery while the vehicle has been stopped for a while.

jf