I have a 2002 Lexus LS430. Recently, the "rear tail light failure" message appeared on the dashboard when the lights are turned on during the evening. There is no message during the day.
I validated and replaced all the light bulbs (including reverse light, 3rd high mount brake light, license plate lights) are the correct type (based on manual) and are all working.

Dealer thinks it is the rear tail light failure module that is out... and estimated cost is around $300++ excluding 2 hours labor @ $85/hr.

Anyone has this same problem and appreciate if you can share how you resolve this issue...
Thanks.

 

There are 4 T10 bulbs in your left and right headlight assemblies: one behind the main reflector, one at the far bottom outside edge of the assembly, on both sides. If any of those headlight bulbs failed, this will also trigger the taillamp failure message.

The taillamp and headlamp T10s are 5W. The T10 bulbs in the interior of the car (trunk, door step lights, etc) are 3.8W, so make sure you replace the headlamps/taillamps with the 5W bulbs.

Do not bother trying to use LED T10s in the headlamps/taillamps - the taillamp failure message will always come on. LEDs are fine for everywhere else.

Can you find out the part # of the taillamp failure module and where exactly it is located? I had a chat with a Lexus dealership service head about this module recently and he said this module almost never fails. He said 1) some non-OEM bulbs are made with a metal base that is not the same as OEM, and this can trip the detection circuit, 2) clean any corrosion on the bulb base and in the socket, 3) a bulb that is on the verge of burning out can also trip the circuit.

I was looking to circumvent the detection circuit so I could try out LEDs, but never figured out where the module was located. In any case, these 5W T10 bulbs are dirt cheap from the dealer, $1.58CAD each after tax, and my originals lasted 11 years/119000kms before burning out.

 

Thanks, Stan.. will replace all the 4T10 bulbs and see if it resolve the issue.