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Strange TACC behavior

Yesterday on a trip from Indianapolis to South Bend and back the TACC would intermittently slow the car down for no obvious reason. There was not a car close enough in front to cause it. Driving conditions were remarkable for fairly high wind; sustained at 25 mph with gusts into the 40s. This is the first time the TACC system did not perform flawlessly since I took delivery in June. I was not using lane keeping due to poor lane markings on US 31. Has anyone else experienced similar behavior? Today on my normal commute everything worked fine again.
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Active Member
Oct 22, 2013
McKinney, TX
It was doing this to me near Georgetown, TX last weekend, in an area of relatively new highway construction. The car suddenly slowed from its setpoint of 70 mph to 50 or so. There were no other cars within miles. It happened three or four times in an area of a few miles.

I wasn't sure if this was anomalous or somehow tied to the fact that perhaps the nav system didn't think my car was on a real road.


Learning Member
Dec 25, 2015
Interesting. I had some incidents where the TACC slowed the car down on an established road. I noticed was that the car had difficulty with the lane markers (terrible road: light colored surface with black metallic grids and white lines on a bright sunny day--presumably reflective). So at one point the car thought that a truck was merging into my lane and began to slow itself down. Don't see it as a problem with TACC, more an issue with a terrible road. I also have significant difficulty using Autosteer on this road.

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