I went to use my RX 450h Thursday when it had an electrical "nervous breakdown." The car would not start, the parking brake would not release, and the headlights acted like a strobe, the dashboard flashed and the wipers started jerking 1/2 inch at a time. The car would not turn off when I pushed the Start button, but finally decided to stop on its own. I called 24 Hour roadway assistance. The driver said the battery was dead. He jump started it so I could get to my Lexus dealer.

I noticed that the car started shutting down accessories to reduce power consumption; such as modifying the A/C (which I turned off) and disabled the BSM. It drove OK otherwise. My dealer has now had the car since Thursday and cannot figure out what is causing the electrical drain. I don't think a battery replacement is the solution.

Has anyone else experienced this? The car will be 4 years old next month but only has 32,800 mile (due to COVID).

Any insight will be helpful.

 

Was the battery replaced? What is the current draw that is apparently causing the battery to go dead.

 

I don't know. Dealer hasn't told me yet; just that they are having trouble locating what is drawing power. Roadside assistance thought the battery needed replacement, but it seems Lexus doesn't think so. Something is drawing a lot of power, because there was a screen warning that the A/C was being modified in output due to high power consumption. When I took the car in, the service rep said they would check all systems. I presume they found something other than the battery is causing the problem but don't know what it is. They stated, "still trying to figure out where the draw is coming from. Checking all electric components."

 

My guess is it's the battery. I noticed the 450h does a bad job charging the 12V battery, which is why they die young. My 2016's "nervous breakdown" happened at 37202 miles at 4.5 yrs of age. COVID makes it even more likely your battery isn't getting enough charge.

 

I have had some resets, like the nav screen going full screen after being parked for a long time, but nothing crazy.
I do toss it on a ctek 4.3 charger from time to time. the car sits, a lot, then goes 700 or 1200 miles in a day. some local use too.

17 (build 11/17) with 44k miles. oe battery

 

Just got a call from my dealer. They found a short in one of the cables leading to the battery. Cable and new battery being replaced under warranty.