I replaced the 12V battery with the correct battery from the dealer but now the car won’t start. I am seeing the check engine light now and i am also see a TRAC OFF come on the dashboard. The battery wouldn’t hold a 12V charge one of the fuel cells was bad according to 2 different places.

It says to enter the car into maintenance mode or something to that affect briefly. I am not sure what I did wrong.

I am not a mechanic by trade soo please don’t be brutal with me. Maybe i did something stupid and i don’t know.

 

It is very difficult to install the battery incorrectly as there is so little room in the trunk. If you got some lights then it was connected properly.
It sounds like they sold you a defective battery. Or - Sometimes new batteries sit for so long on the shelf they really need to be recharged before being used.


I would take the new battery back to Lexus and state it appears to be defective and demand they test it and replace it.

When you said it would not hold a charge etc was that the new battery or old battery?

 

This is the new battery and i am seeing that it definitely has life to the battery cause the lights are on and dashboard comes on. I am not 100% sure that it needs to be replaced also but i will take it to a local shop to see if it is good or not.... then if it isn’t then i will take it to Lexus.

 

You can also take the new battery to an O'reilly Auto parts store to have it tested to confirm if the battery is defective. If defective go back to Lexus and they will warranty if out and get you a new one. Be sure to check the battery connectors to make sure they are not corroded and clean them with a battery terminal/connector cleaner. Hope that helps. Keep us updated.

 

I used to own the HS. There is a reset procedure inside the fuse box in the engine department. I think you have to pull a fuse and plug it back.

 

That may be true and I was not aware of this reset procedure. However, when I replaced my battery in the Lexus dealer parking lot I merely swapped batteries and drove away.

 

To the OP, given that one member did the reset and another did not, now may be a good time to review the process in your owner's manual and follow that and see what the outcome will be for your situation. Please update us to your findings.