On Friday night, the weather turned nasty on I-35 N in Iowa. My DRCC was engaged (78 mph) and working fine until the skies opened up and the rain became very intense, but the car was driving steady with no issues. Suddenly, the car slowed down and I noticed the dreaded yellow warning triangle was lit. Within a couple of seconds, I realized the DRCC had disengaged automatically. The warning light went off when I turned off cruise control. I reasoned that the intense rain had confused the DRCC system, causing it to disengage. Over the next 30 min, the rain subsided greatly, but there was still a mild drizzle, very wet roads, and much spray and mist from other vehicles. Surprisingly, I could turn on cruise control but it would disengage within several seconds. I am pretty sure this is due to the radar signals not behaving normally under these conditions. DRCC functioned fine on the drive home yesterday.

I don't think standard cruise control would disengage automatically under such conditions. Or would input from stability and traction control systems disengage cruise control?

 

I've never had standard cruise disengage and I've driven in every type of weather imaginable. It works in excess of 120mph too. haha

 

I haven't had an 'opportunity' for radar cruise to disengage itself . However, on the manual it says not to use during snow / rainy days among other few exclusions. That's one of the main reason radar cruise wasn't offered in NE region in the past. Things might have changed now.

Standard cruise wouldn't disengage in such conditions.

 

Anything that can "cloud the sight" of the sensor behind the front "L" will deactivate the system. I have had it happen once or twice in heavy rain. On treated roads in winter, I imagine the problem would be much worse, but I don't take the car out on that stuff :-)

Regular cruise doesn't disengage under the same conditions, as others pointed out, as it's not "looking" at anything. However, it will disengage if your traction control kicks in multiple times and under some other unique circumstances I can't remember (but have read somewhere).

 

This is normal, have experienced it couple of times in moderate to heavy rain.

You also have the option to use regular cruise and bypass the radar. This will not disengage.

 

Really? How do you do that? As soon as I turn on the CC button, the system says "Ready". When I set the speed by pushing down on the stalk, CC is engaged, and I see the car displayed with the radar distance setting on Max. I can then push the DRCC button to cycle thru the distance to shorter lengths, but it doesn't turn off.

 

Push the lever away from you.

 

Relevant page from the Owner's Manual...

 

Thanks, y'all, I will try that next time. I guess it pays to read the Owner's Manual from cover to cover

 

so you don't hydroplane.

 

I confirm all of the previous as well... went through the issue several times.

But do not use the regular cruise in that weather... if it's not good the electronic way, it's certainly not good the human way as well...

 

All cars equipped with Cruise Control come with a warning not to use this feature in conditions where the drive wheels might lose traction with the road surface, such as wet, icy, snow covered or loose gravel. Cruise control is automatically canceled if the VSC or TRAC is activated.

 

When I am driving my Legacy or Sienna in inclement weather, I can feel and hear the buffeting, the rain and wind noise, and turn off cruise control. In the 460, everything was rock-steady and serene even with the heavy rain that I didn't notice the need to disengage cruise control until the sensors turned it off. I guess the e-nanny was looking out for me and the family

 

I have an 04 LS with radar cruise and I've had it turn off only twice. Once was when I was driving home to San Diego from Phoenix thru the desert and the sensor got covered with bugs. lol.
The second time was in very heavy rain. Wasn't safe to be driving on cruise anyway.