"Cruise Control Operation Question"


When I turn on the cruise control on my 2005 LS430 a display pops up on the dash where the temperature is usually displayed and say's "RADAR READY".


At this point, if I engage the cruise control by pushing down the cruise lever the dash board flashes a warning to "Check Cruise Control" and of course cruise doesn't work.


BUT......


If I turn on the cruise control and then push the cruise lever forward before pushing the cruise lever down to engage the cruise control everything works just fine.


I looked at the Lexus Badge in the front grille and it is not solid but has an opening all around the "L". There is also no wire harness going to this area of the grille.


Apparently I have to do this extra step each time I want to use the cruise control?


Anyone else experience this?


Thanks in advance


Bob

You most likely have laser cruise control, like I do, and there is a problem with the laser module. There are two modes - laser, which they call radar and is odd, and normal, the one that works. The laser module is located on the lower front bumper on the passenger side. Double check it is not obstructed by bugs or the glass covering is not broken.

Looks like this:

Great, I'll take a look


Thanks very much for the reply


Bob

Just took a look at it as you described and washed the glass lens.


Took a ride with the same results. Once the system faults the cruise control can't be used until the ignition switch is turned off and the car restarted.


At least it works in the normal mode.


Again thanks for your help.

Sorry to hear it is broken. It actually is a nice feature as it will pace itself behind the the car in front of you and you can adjust the distance it will pace. It will even apply the brakes and sound a warning signal if the car in front of you hits the brakes and slows down quickly. You could probably locate a good used module through eBay or Car-Part.com which does nationwide salvage.

Edit: Might be worth checking if there is a fuse associated with the module and making sure it is not blown.

There were a couple replacements on car-part last time I was browsing ls430 parts.

Is there condensed water inside the lenses by chance?
Additionally, with the car idling and Radar Ready, do you see the mirror spinning if you look through the lenses?

Found the problem, replaced the Yaw Rate Sensor with a second hand unit from a junk yard and the Cruise control now works in both modes.

Nice job. If you have Techstream or someone that can do it so a zero point calibration as well.

So which year did they switch the sensor to the "glass looking one" on the front grill, as opposed to the one on the bumper, like this one?

Two different kinds ... the one in the grill in your pic has the collision avoidance system. The one in lower bumper is the laser cruise only.

The very early 2004's had the laser, lower bumper radar. Within a few months of the 2004 introduction they quitely switch to the newer version radar. I've always assumed that was because they did not have the later version in production readiness at the introduction.

This is the story -
First, the discussion applies ONLY to Custom Luxury (CL) and Ultra Luxury (UL) cars. The Adaptive Cruise Control systems Dynamlc Laser Cruise Control (DRCC) and Dynamic Radar Cruise Control (DRCC) were not available on Base, Premium, or Modern Luxury (ML) cars.
The CL or UL cars could be ordered either without Pre-Collision System (PCS) or with it. These are 2005 prices:
CL without PCS was code LP for $5935, with PCS was code LQ for $8185.
UL without PCS was code UL for $11320, with PCS was code UN for $13570.
DLCC was standard on the non-PCS cars. DRCC was included with the PCS feature.
The PCS feature was available on the model year 2004 cars, but as far as I can tell, was not manufactured until about Jan 2004.