Might not be the correct subforum so Mods please feel free to move/delete if so.

Hello! So I own a 2023 500 that I purchased new in December of 2023. Currently at just under 9000 miles. Haven't had any major issues with the car so far, and I wouldn't really expect to. Yesterday as I was approaching my parking garage the CEL came on with a chime and the engine turned off. This was followed by "Charging System Malfunction" on the center display. I stopped, waited a few minutes, and then started it back up without issue. Proceeded to park and start to do some research. General consensus online seems to be either battery is dying or possibly the alternator? I guess the main reason for my post is to ask, are alternators a known issue with the current IS line? I haven't really read anything specifically about them being problematic. I would assume the battery to be a more likely culprit, however I just had my car serviced at Lexus last week on the 10th and the battery was in good health per their testing. I've ordered an OBD2 scanner so I can see if I can find any codes, should hopefully arrive later today or tomorrow. About an hour after this occurred, I started it up again and drove to meet my family for dinner and I did not have a recurrence of the issue going to or from.

Has anyone else experienced issues with the stock battery dying within two years, or problems with an alternator? And if you have had the battery go out, did it produce the same error message that I received?

Thanks!

-Matt B.

 

^^ I am not aware of any owners having issues with the battery or alternator - That is not to say that yours could be an isolated case. I think you are on the right track with any of these two as being the potential culprit and could be a bad cell in your battery or something. Do you tend to drive your car over somewhat long distances or only short trips as this can be harder on a battery. I usually put mine on a battery tender periodically to ensure it gets fully charged when I don't drive it much or park it for the winter, The only issue that you haven't identified could potentially be a rodent that may have chewed some wires also potentially giving some issues.

Are you close to a dealership because the car should be under warranty (unless you have exceeded the mileage already.

Keep us posted

 

Work is approx 13 miles each way, though I only have to drive that three times a week. Sometimes the car will sit for a day or two. It's always garage kept, both at home and at work. I popped the hood and looked around but didn't see any immediate issues around the battery area. Live near Los Angeles so I drive it year round and temps are pretty moderate. Dealership isn't far, just have to battle traffic to and from. I'll see what the scanner shows and I'll call them after.

Thanks!

 

That driving distance should be enough to keep it charged up properly

 

The engine must be running for the charging system to operate, if the engine stalls, the charging system warning will be displayed.

Engine stalling may be an issue with the throttle body. Review the system faults in the engine controller.

 

^^^ This. Especially since you drove it again with no malfunction. A bad battery or alternator would not let you drive again without instant recurrence and the reason for the stall would not necessarily be a bad battery or alternator.

 

So the OBD2 scanner came in (Ancel BD310 for reference). Connected without issue. Two separate ECU's show up in the system and neither one has any codes. Also has a battery test function and it shows the battery voltage hovering around 14.05 with the engine on, idling. Seems to be within the normal range from what I can tell.

 

Your TB might be going out. This car does really weird things when the TB starts acting funny. Random and unrelated CELs and driveability issues. Extremely common issue around your mileage too. Mine was done at 7k.

 

Yea, I'm worried that might be the case. I'm going to keep driving normally and see if it occurs again, but I'll still be calling Lexus to setup an appointment for them to check it out.

 

^^ and I am sorry, I hadn't read the part of the car stalling which wouldn't be a battery issue so my bad for that, Quick trip at the dealer might be an order and if it's the TB, there is a TSB for hose replacement and such but I think those also triggered codes. Dealer will take care of you Keep us posted

 

Minor update:

no additional engine shut off or CEL. Checked again and no codes I can read. Haven’t had a chance to get it to Lexus yet.

I did notice the following in the short clip I’m posting. While idling and the engine is cold, it seems to be having a hard time keeping the rpm’s steady. The clip shows the biggest fluctuation I saw while recording for one minute. Behavior disappears once it’s warmed up. Assuming this is something that could happen if the throttle body is sticking/not opening properly. Could also maybe be fuel related. Just seems odd that it doesn’t throw any codes.

 

Wanted to chime in, I’d get the throttle body replaced asap. A guy on FB had the same symptoms and Lexus replaced both fuel pumps before realizing it was the TB. The fuel pumps have been issues for some, but for you, I’d have the TB replaced first. Especially since the fuel pumps are not kept in-stock (in some areas), take weeks to come in, and they’ll only replace one at a time. e.g.; Requiring multiple trips.

 

I appreciate the input. Going to give the service department a call and see if I can get it in soon after the new year.

 

Welcome and good luck!

 

Wanted to post a quick update:

Life got hectic and no issues had reoccurred so I delayed getting the car into the dealership. However, today the CEL and multiple errors came on and the CEL stayed on this time. Was able to pull the codes with my reader and came back with the following:

P1170 - Fuel performance/port injector
P0174 - System too lean bank 2
P0171 - System too lean bank 1

Dropped the car off at the dealership today and got a loaner. No update on the specific issue yet since it happened rather late and they were barely able to squeeze me in a few hours before closing, but I'll report back when I have more info. While I was there, I spoke to the service rep about getting the transmission TSB. Given that it's not a recall, he wasn't 100% sure that it could be taken care of, but he added transmission downshift clunkiness to the report/request (Not a fabricated issue in my case either, it does actually downshift harshly, especially when cold) so we'll see what happens. Hope to have more info in a few days.