Hi, we have a 12/18 EC that will not hold cruise control spend on undulating roads.If set to say 110 it will slow going down a gentle hill to say 94, stay there on the up hill for a few seconds then race to 118 well over the set speed setting.This is when the radar cruise is not picking up vehicles close by. The other problem is the emergency braking ,when set on cruise control it will activate the brakes by its self when you are merging from two lanes to one lane.It seams to pick up the vehicles coming from the opposite direction and jams on the brakes.Both these problems have been raised at the selling dealer who says that they are not a problem.No so good with a truck on your tale, location is Victoria Australia
I am experiencing cruise control behaviour very similar to Wassa and others. (I realize it may be a little late to revive this 'old' thread.)
I have an EC PHEV Exceed purchased new in Feb 2022. We have just completed a 20,000km trip around Australia. The cruise control was engaged at 95kph for most of the trip. We were towing a 850-900kg camper trailer. At 100kph, higher fuel consumption compromises the range available from the 45L tank. Fuel stops can be up to 400km apart. A 15L fuel reserve carried on the camper was accessed twice.
Around 80% of the time, the cruise control held a tight tolerance of +1kph cresting hills/rises and -2kph going through dips or at the start of a climb. If the speed control was tight at the start of a driving session it stayed tight. The rest of the time the cruise control maintained tight overspeed control of +1kph but, coming out of a dip or at the start of a climb, the speed would consistently decay to 84-87kph before recovering. If poor speed control was evident at the start of a driving session, then it remained that way. Briefly pulling over and rebooting the car (switch off/on) did not resolve the issue. At the start of a day or after fuel and other stops, it was not possible to knowing whether speed control was going to be tight or slack.
The vehicle also exhibits momentary braking when lane merging with cruise control engaged in the presence of oncoming traffic. The behaviour is common at the end of overtaking lanes and occurs whether the traffic indicator is on or off during the lane change and whether or not there are close dashed line markings in the merging zone. (Western Australia doesn't have close-dashed lane markings in the merging zone at the end of overtaking lanes.) Typically, the braking washes off about 20kph.
I have not yet discussed the issue with a Mitsubishi dealer. Also, the windscreen was cracked half way through our trip and is soon to be replace. I will be interested to see if the sensor realignment done during the windscreen replacement, changes the cruise control behaviour.