2016 Honda Civic: Malfunctioning Adaptive Cruise Control
by Brent Romans, Senior Automotive Editor on July 27, 2016
During my recent highway-heavy drive-fest in our 2016 Honda Civic, there were a couple of instances when the Civic's adaptive cruise control system (ACC) suddenly stopped working. At the time, I wasn't sure if it was an isolated problem or something more systemic. Then it happened again yesterday.
When the problem first reared its head, I was driving on the highway and had selected the ACC's shortest following distance. The system had been working fine, but then a slowing vehicle ahead required it to apply the brakes, and instead it became indecisive and/or confused and didn't brake as much as it should have. After that, the ACC switched off completely, followed by a bevy of warnings that popped up on the driver information display.
Collision Mitigation and Road Departure Mitigation weren't working, either.
The "Brake System" warning light was also illuminated. (Note that the parking brake was engaged in these photos, so the red "Brake" light wasn't a malfunction.)
I was paying attention when it happened, thankfully, so there was no danger of rear-ending the vehicle in front of me. The brakes (driver-operated!) still worked. I was a little rattled, though, so I pulled off at a rest stop and turned the ignition off and back on. All of the warnings disappeared. According to the Civic, everything was A-OK.
I got back on the highway and a similar scenario played out an hour later. At that point, I thought maybe it had something to do with all of the highway driving I had been doing; maybe the ACC sensor (located in the front bumper) was covered with bug guts, affecting its performance. I stopped again, switched the car off and on, and that seemed to be the end of it.
But yesterday it happened for a third time, and I know it didn't have anything to do with a dirty sensor since I actually looked at it this time to confirm.
The system still worked normally for the vast majority of my time in the car (more than 1,400 miles of driving, mostly on the highway). When the first hiccup happened, I was driving at lower speeds (slowing due to highway construction), while the other instances were perhaps around 60 mph. For what it's worth, the lane departure warning and intervention system continued to work normally.
It's too bad this ACC problem happened after we had the car in for its recent first service. Otherwise, we could have brought it up with the service advisor then. As it is, we'll likely have to schedule a separate appointment.
Brent Romans, Senior Automotive Editor @ 9,045 miles