The cruise control lost 5 mph at 59 mph and gained 2 mph over 59 mph when the vehicle topped hills. I also checked the system at 69 mph, 74 mph, & 79 mph. The problem was less noticeable at higher speeds. I've had the dealer look at it three times and even contacted GM Customer Assistance. They claim the cruise control is working properly. This is very aggrevating and caused significant problems in high traffic volume areas of I-20 between Atlanta, GA and Florence, SC, where I encountered moderate hills.
The cruise control lost 5 mph at 59 mph and gained 2 mph over 59 mph when the vehicle topped hills. I also checked the system at 69 mph, 74 mph, & 79 mph. The problem was less noticeable at higher speeds. I've had the dealer look at it three times and even contacted GM Customer Assistance. They claim the cruise control is working properly. This is very aggrevating and caused significant problems in high traffic volume areas of I-20 between Atlanta, GA and Florence, SC, where I encountered moderate hills.
- kevmc78, Fayetteville, NC, US