I had the exact same problem. It started one afternoon on my way home from work. I got to my Civic and realized my taillights were on. It appeared that I had mistakenly left my lights on, but they were turned off. I drove home and noticed that the cruise control would not engage. When I got home I examined my fuse panel under the dash and noticed blue pieces of plastic on the floorboard, which turned out to be the remains of the brake light switch actuator. This is the device that turns of the switch, which in turn turns off the brake lights (they are activated when pressing the brake pedal and the actuator is removed from the switch, turning it on). This was a very simple fix. I just inserted a plastic retainer clip, like you would used on a door panel, and now my brake lights turn off and the cruise control engages. The brake light switch is a 4-conductor switch on the LX and EX models (both equipped with cruise) and a 2 conductor on the DX (without cruise). So, whenever your brake lights are on with your foot off the brake and your cruise control will not engage, always check to make sure your brake light switch actuator is in place and not broken.
Thursday, November 15th, 2007 AT 8:25 PM