So with yesterday's coastal storm on the Long Island roads were not in good condition particularly due consistent heavy rain. I was driving on the country road in the night at 50 MPH all of a sudden I hit a huge puddle which I definitely didn't see/anticipate. Truck hydroplaned a bit but I was able to control it and as soon as I hit it 4LO and Difflock lights on the dash started to flash consistently. I stopped the car and tried to engage difflock which didn't work. I tried to engage 4LO and nothing happened. Flashing lights woudn't go away. After reading multiple threads on mud no body seems to have encounter this specific issue but close. People tried to exercise the difflock and it would start to work again. But for me it wasn't happening at all. I tried to put the car in N and powered off the engine. Engine turned off and dash went dark but Navigation stayed on... which is super wiered.. After restarting lights disappeared. Next I tried to engage 4LO which worked and 4LO light went solid and I drove it a little, later I also engaged Difflock and that worked fine. I drove it on the grass a little and then swtiched back to 4HI and disengaged the Difflock. I thought now its fixed. After that I turned off the car, restarted and same thing 4LO and Difflock lights flashing and none of those would engage. Car drives fine with those lights flashing. No issues with drive so far.

 

i know nothing about what is underneath an LX.
but you DID say it started after driving thru a deep puddle.

i would get under there with some electronic contact cleaner and some non conducting nylon brush, and open up every electrical connector that even vaguely looks like it is related to the drive train....then clean the connector inside, add some dielectric grease, and reinstall. say a few prayers and see if that fixes it.

sometimes dirt and corrosion build up on the contacts, and you add a little water and POOF! NO BUENO!

 

Thanks for the great suggestion. That I think I will do if it happens again.

 

**** UPDATE****

Took it to the dealer with the same condition for diagnostics. After an hour of wait, tech came back and explained that he had done a master reset with their scan tool and hopefully that will fix the problem. So I drove back home. Problem started to happen again for another day and then it disappeared. So I guess clearing the code had an effect and ECU probably recognized that there is no issue. So far so good. Main issue with my truck is that it stands for extended periods of time i.e. 4-5 months at a time as I spend a lot more time overseas now. Usually when I come back the I have to jump start it and engine makes weird noises and everything comes back to normal with couple days of driving.

 

Wondering why you don’t hook it up to a battery tender while you are away? Just maybe the electrical drain is the root of these gremlins you are experiencing. Battery Tender even makes a solar panel charger you can put on the dash. Lexus installed the Battery Tender connectors and gave me a Battery Tender (complete with Lexus logo on it) when I asked about the battery drain issue. No charge for wiring or the device, it was a good will gesture by Lexus. I bought the solar panel myself later for times when I had to park too far from an electrical outlet. I do sometimes park on the roof of parking decks for sun access.