That would be my first thought, a defective parking sensor.
There is a volume control for the beeps. It's under the dash on drivers side, near the center stack. It also has a click that I assume turns the beeps off. The car does have different beepers, for different things. If the beep is coming from the back it's the back parking sensor or sensors. I think that is way cool the way it beeps in the back if it's the rear parking sensors, very cool.
Might help to turn the beep off or way down until you get it sorted out. I would recommend a cable and techstream to figure it out.

 

 

Mine only beeps once for that. Your manual will tell you how to connect your phone. Pretty sure it is in the nav manual. If your manuals are missing the Lexus Drivers site on Lexus.com has the manuals, and your service history too. Sign up using your VIN.

 

Thanks Ricklin! I did try the **** under the dash but didn't seem to lower the volume of the beep or turn it off. I do have all the manuals so i'll read up on that tonight at least get rid of one beep.
The beeping is coming from the front somewhere, tried turning off the parking assist too and that didn't work.

 

I had the same issue last summer but it only lasted for a couple weeks so I understand the frustration. I'm still not sure what caused it but I do have a couple theories...
It started one night on a 25 min drive and, unbeknownst to me, I had a screw in my front tire. I didn't know about the screw until the next morning. The tire was repaired the next day but the beeping continued. When it was happening on occasion I couldn't access climate controls. I'd press CLIMATE and nothing would happen. Sometimes after several minutes the CLIMATE button would suddenly work for me. Sometimes turning the car off and back on would fix the issue, sometimes not...
Another thing I noticed during this time was intermittent issues with my clockspring. My stereo volume would change randomly up or down when hitting a bump especially when the steering wheel was turned. Stereo controls on the steering wheel wouldn't work properly or at all.
I still don't know if either of these issues was linked to the random beeping. The tire was repaired asap and the clockspring only acts up about twice a month now so I don't feel a pressing need to replace it.
This may not help you at all it's just a couple things I noticed last summer when I was pulling my hair out...

 

Very interesting, these are the exact same issues that I am having but without the flat tire.
What is the clock spring?

 

A very long, approx 8 or 10 feet IIRC, cable coiled up in a spring apparatus just behind the steering wheel airbag. It allows all the controls on the steering wheel to function as the steering wheel turns.

 

The **** under the dash, above the driver's right knee is for the external beeper of the car, indicating the locked/unlocked status of the car, and other "alarms" that need to be transmitted (via beeping) to a person OUTSIDE the car. That **** IS NOT for the parking sonar sensors. The parking sensors are turned on/off (and thus the parking sensor alarm beeping) is shutoff via the pushbutton shown here...

 

Roger that, I tried turning off the parking sensor as well but didn't have any luck with that either.

 

The LS430 has several different beeps:
1) parking sensors
2) door lock confirmation (controlled by **** to the right of the OBD2 connector)
3) dashboard warning triangle
4) nav screen touchscreen / nav screen side buttons
5) audio system beep through the speakers (holding the steering wheel UP or DOWN buttons to switch CDs, for example). Any audio sources trying to register itself on the AVC-LAN will also cause an audio system beep.

The original post seems to indicate nav screen button or screen contact. Check the nav screen by entering diagnostic mode as follows:
1) Vehicle speed = 0, parking brake ON, headlamp stalk OFF
2) Ignition ACC or ON,
3) Press and hold the nav OPTION button, turn headlamp stalk to TAIL (one click), then OFF, then TAIL, off, TAIL, off.

You are now in service check mode. Take note of any error codes (or take a picture of the screen and post it here, don't clear the codes or press recheck). Then hit Menu, then enter Display Check, then do the Color Bar Check, Touch Switch Check, and the most useful one in this case, the Panel Switch Check. Report back what you find - do all buttons and all parts of the touchscreen work correctly, or are some glitchy?

By any chance did anyone install an iPod integration kit into your nav screen? Some kits automatically press the "I Agree" button on the startup warning page, which can cause the beeping you are hearing.

 

Thanks Stan, I will check this our for sure and report back.\
I did find a power cord coming out of the left side of the dash that I had missed when I bought the car. it was hiding pretty well and tucked in the lower part of the dash by the parking brake, my best guess is it was power for a radar detector?

 

Yes, that power cord from the fusebox is likely for a dashcam (normally a barrel plug) or radar detector (RJ11 phone jack plug), should be unrelated to the beeping you're hearing.

 

can't seem to upload pictures but everything seems ok except the AUDIO H/U has a yellow "check"?

 

Was the fix for this ever determined? I am having the same issues.... Climate and Audio buttons beside the NAV not working, random beeping every 10 seconds, steering wheel controls not functioning, random volume changes....

Any update or additional information would be helpful!