When I start the car, it goes through all the checks and everything is fine. I can turn the cruise control on w/ radar and it is fine. As soon as I try to engage the cruise, the red triangle appears and the "Check cruise control system" message appears.

I have reported this problem before on this forum and had Lexus actually fix the radar portion ($300 labor). The radar again does not work and I have to Hack the cruise control to have the cruise control portion function. When the radar was working it was an awesome feature, since it adjusted the speed of the car in relation to the car in front of you.

Reason I am reposting is to see if anyone has had the same experience and their solution.

2005 LS430

 

Have you inspected the send / receive unit in front of the car for damage or dirt? I have the laser cruise with the send / receive on the lower right bumper and I keep an eye on it for road damage. I also wash it gently every time I hand wash the car.

You're right - it's an awesome feature but subject to damage and expensive to fix.

 

Yes I have checked and so did lexus dealership. They were able to get it working by calibration, and then a few weeks later it didn't work. I suspect that the mechanic that knew how to fix it was not there the second time around. Lexus then stated that since the car had been in an accident that I should return the car to who ever fixed the car. I explained that the accident occurred three months after the purchase in 2005 and that I had no issue with the radar sensor. Very frustrating.

 

I had the same issue when I purchased my '04 LS430. Fortunately, I bought it from a Toyota dealer, and they recalibrated the sensor and so far it has been great. I am told that it is $3,500+ to replace the sensor.

 

I noticed you have a 2005. By any chance did you drive more than 200 miles straight w/ the radar cruise on? Many of the 05's w/ radar (since it was the first year) have a bug in the radar ECU. It'll throw a code when you try to engage the radar. Do a search on it in the archives. The same thing happened to my '05 w/ PCS radar. I bought the car CPO in late '09 and drove it locally for a year. PO were retirees who never really left town. Anyways, the day I moved out of state, I drove 450 mi. After having the radar on for some distance, it threw a code. At the next stop, I checked to see if dead bugs on the clear radome were the problem. I cleaned it, but still had the problem. I wasn't able to use the cruise, even the non-radar cruise (in fact, that's what I was using when it threw the code). Searching the archives, I found there is a TSB on it. Told the dealer about the TSB, they verified that was the problem, and replaced the distance ECU under warranty (otherwise, it's $800!).

 

One of the local mechanics thinks that he can fix it and wants to take a look. I live in Howard Beach NY, so most of my driving has been local. I have to set the car for cruise when in a stopped situation. At least that does work.