I finally got around to trying out the cruise control early this AM on the way to class. The light on the switch was on, no cruise set. Looked after getting to work and saw the posts about the 3rd tail lights so I popped off the cover and had someone step on the pedal with engine running, all bulbs are okay.

I noted the post about the brake switch and effects on the cruise control so I looked under the dash and I have two switches, one for brakes with two connectors and one for cruise control with one connector. I noted in the post on these that you are supposed to have to step on the brake to start the car and in the 3 weeks I have had mine, I have not had to do that? Hummmmm, sounds like either a switch is failing or they are slipping out? The brake lights come on with normal pressure so I think that one might be okay? Not sure about the other switch?

Is there an adjustment setting, such as all the way in or some fraction of an inch? Thanks for the help.

Update, I checked the owners manual and it sez you only have to be in Park or Neutral to start, no foot on brake required.

 

foot on brake to put in gear.

After you turned the cruise on (light on button) did you push the "set" button at the desired speed (over 25MPH)? Kind of sounds like no.

 

Yes, I do the foot on brake out of habit. After pushing the cruise switch I did try the + and also the - buttons both by holding them and pressing them several times. I also tried holding the cruise button for a few seconds as I thought there might be a built in delay as the cruise control moves the system into the speed the engine is running? Nope not any of those.

With the Ford F350 I had there was a slight delay as the brain took over from the throttle position switch. There was no "throttle lever" such as older cars had.

I was thinking of taping the "cruise" switch so it looks like the brake is off no matter what and trying to see if there is any play in the plunger on either of the switches when the brake pedal is fully back? I have found as I have gotten older (much older) it has become harder (much harder) to get under the dash to work on things like these switches!

 

Were you getting a "Cruise Engaged" message on the DIC?

 

Nope, no message on the dash. That's why I thought it was the switch possibly?

 

Another thing to look into may be a failing TCC (Torque Converter Control) solenoid. When they fail the BCM will get a false signal that tells it that you have the brake pedal depressed when you actually don't.

Have your codes pulled at your dealer or local auto parts store, if its a bad TCC solenoid you'll see a code P0741 if memory serves me right.

 

I did not mention it in my first post, sorry, but I checked for codes when I got home after the first try at running the cruise control and there were none. I use AutoEnginuity with the expanded Chevy module so somewhere around 300+ sensors are read and nothing showed up.

I replaced all four of my 3rd eye light bulbs and we'll see if that help? Easier than crawling under the dash.

 

Read the Cruse Control section of the Owner Manual! You are not describing the (simple) procedure described therein. It does not operate the same way a Ford does. Do not hold the SET- button down, TAP it. The RES+ button is used to either resume after stepping on the brake or to accelerate while in cruise mode. "Cruise Control Engaged" will only display momentarily.

 

I tried tapping the switch and also holding it but no difference as I said earlier. I also tried tapping and holding the + and - switches and watched for the message to come up, either to stay or be momentary. This morning I did replace all four 3rd brake light bulbs and that also made no difference. So after lunch I crawled under the dash and using a mirror and light looked at the switches. I found they have a rubber bumper in the steel plate that the switch plunger IS SUPPOSED to touch and on both mine the switch had tilted slightly so the plunger was hitting the steel instead of the bumper. I pulled the cruise control switch, unhooked it and checked it with a meter for open/close and then put it back in sliding it far enough so that the plunger goes all the way in.

Did a test drive and what do I find......the cruise control works just fine as supposed to now! It appears the bushing the switch snaps into has gotten tilted slightly so this may be the fix for others?

 

I did not see any bushing. I just replaced my switch. Sometimes you have to slam on the brakes a few times then cruise will work. Ac delco part also