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On one cold day back in December I was gearing up for my morning dive. Because it was pitch black outside I thought it would be a good idea to leave the lights on (come/leave home stays on until the car is locked). The lights were on for about 40 minutes. I then locked the car (RX500h). Hazards flashed, buzzer beeped. I came back an hour later and popped the hatch open. The car beeped again and hazards flashed. And this is where the problems began. I tried opening the side door but to no avail (gotta thank Lexus for those idiotic electronic release handles). Pressing the unlock button on the fob only resulted in flashing lights but no buzzing. Doors were still locked. I had to climb over the back seats to reach the rear door manual release handle. Once the doors were open I tried starting up the car. It beeped again but the dash didn't even light up. Dead battery symptoms... Luckily another diver was parked nearby and had jumper cables. We jumped the battery and the car started right up.
Two weeks went by with zero issues.
Having feared being left alone with a dead battery in the middle of nowhere, I decided that my wife's husband deserves another Christmas gift in a form of a booster.
Sure enough, couple of days ago I had the same issue. No lights were running before locking the car but same symptoms came up again. The hatch opened no problem but then the car died on me again. The booster was put to its intended use and voila the car was brought back to life.
I blame the battery but wondering if this happened to anyone else. The car is less than a year old and Lexus keeps scoring top three across all known reliability charts. My next servicing is coming up soon so I will definitely have them look into it but my guess is that they will offer a battery replacement at my own expense.
Kinda ironic that a hybrid car is immobilized because of a dead battery.
Last edited by tecdivingaccountant; Jan 16, 2024 at 05:49 AM.
My 2024 RX450h+ was draining the 12 V battery whenever it sat for a few days. I bought a battery monitor on Amazon that tracks battery voltage and downloads data to the phone. I noticed a cyclical draining of the battery when the vehicle was off. I measured fuse voltages (vehicle off, doors latched) and found the drain was thru fuse ECU-DCC No. 3. I put a fuse extender in and monitored the current thru this fuse. (Fig. Below). Something was evidently turning on and off continuously (vehicle off) and drawing a lot of current. One of the items on this circuit is the Bluetooth Digital Key receiver assembly. (The Digital Key system uses an App on the cell phone to lock/unlock doors and even drive the vehicle without the key fob.) By chance I noticed that the cyclical discharging of the battery was triggered by the garage door opener! (See Fig. Below). It seems the Bluetooth Digital Key receiver was responding to the garage door opener, cycling on and off and discharging the battery. When I disabled the Digital Key system in the car (Settings -> Info & Security -> Enable Digital Keys -> OFF), the problem went away! I’m still able to use the Lexus App to unlock/lock the car, and see info about the vehicle (linking to it through cell phone or WiFI, I guess). But beware the Digital Key—it seems to be a source of serious parasitic battery drain.
On one cold day back in December I was gearing up for my morning dive. Because it was pitch black outside I thought it would be a good idea to leave the lights on (come/leave home stays on until the car is locked). The lights were on for about 40 minutes. I then locked the car (RX500h). Hazards flashed, buzzer beeped. I came back an hour later and popped the hatch open. The car beeped again and hazards flashed. And this is where the problems began. I tried opening the side door but to no avail (gotta thank Lexus for those idiotic electronic release handles). Pressing the unlock button on the fob only resulted in flashing lights but no buzzing. Doors were still locked. I had to climb over the back seats to reach the rear door manual release handle. Once the doors were open I tried starting up the car. It beeped again but the dash didn't even light up. Dead battery symptoms... Luckily another diver was parked nearby and had jumper cables. We jumped the battery and the car started right up.
Two weeks went by with zero issues.
Having feared being left alone with a dead battery in the middle of nowhere, I decided that my wife's husband deserves another Christmas gift in a form of a booster.
Sure enough, couple of days ago I had the same issue. No lights were running before locking the car but same symptoms came up again. The hatch opened no problem but then the car died on me again. The booster was put to its intended use and voila the car was brought back to life.
I blame the battery but wondering if this happened to anyone else. The car is less than a year old and Lexus keeps scoring top three across all known reliability charts. My next servicing is coming up soon so I will definitely have them look into it but my guess is that they will offer a battery replacement at my own expense.
Kinda ironic that a hybrid car is immobilized because of a dead battery.
Don't forget there is a manual door lever under the exterior door handle. Page 544 in the Owner's Manual (350h & 500h) shows how to unlock the doors with the mechanical key then you use the door lever to open it.
Don't forget there is a manual door lever under the exterior door handle. Page 544 in the Owner's Manual (350h & 500h) shows how to unlock the doors with the mechanical key then you use the door lever to open it.
Every door on this car also has a manual lever. I am unclear on how they work on the other doors though. The manual says unlock the drivers door with mechanical key in order for the manual lever to work, but how do the other doors get unlocked if the battery is dead????
This whole electronic door latch is dumb idea! What was wrong with the door handles that were proven and were reliable??
Don't forget there is a manual door lever under the exterior door handle. Page 544 in the Owner's Manual (350h & 500h) shows how to unlock the doors with the mechanical key then you use the door lever to open it.
I'm aware of that trick but I have a bad habit of detaching the fob from my mechanical key so I don't have to carry all of my home and work keys around with me all the time. Might have to come up with another solution so the car key stays in the key fob.
It's too bad there isn't a way to use the hybrid battery to jump the 12 volt battery. A built in toggle switch to funnel some of that juice to the 12 volt would be nice.
Every door on this car also has a manual lever. I am unclear on how they work on the other doors though. The manual says unlock the drivers door with mechanical key in order for the manual lever to work, but how do the other doors get unlocked if the battery is dead????
This whole electronic door latch is dumb idea! What was wrong with the door handles that were proven and were reliable??
You have to do each one individually but hopefully you would only need to do one then resolve the issue as to the dead battery.
You have to do each one individually but hopefully you would only need to do one then resolve the issue as to the dead battery.
My car has a mechanical key hole only on drivers door. I am still not sure how to use the mechanical leaver on the other doors. I will have to test it with the battery connected to see if unlocking the drivers door with mechanical key will allow usage of the mechanical door lever from outside.
Talk about complicating things for ABSOLUTELY no reason.
My car has a mechanical key hole only on drivers door. I am still not sure how to use the mechanical leaver on the other doors. I will have to test it with the battery connected to see if unlocking the drivers door with mechanical key will allow usage of the mechanical door lever from outside.
Talk about complicating things for ABSOLUTELY no reason.
First turn of the physical key unlocks the driver's side. Turn it again and it will unlock the other doors. Assuming you have battery, of course. If not, then I'd think you're left with pulling the physical lever on the inside of each door. One pull activates the lever as mechanical, 2nd pull unlatches. Got to agree with the "why" is this necessary, tho'. I know it's for the "active assist" so you don't open the doors into on-coming traffic. But, yeah, what was wrong with door levers we knew worked? I'd think these "safety features" could have still been implemented on standard door levers. My muscle memory still misses the real handles.
Dead 12v battery Incident (merged threads)
