Australian Car Repair Issues? Ask an Auto Mechanic for Answers ASAP
I am sorry that you have not been helped yet. I just came online and saw your question
Can you clarify some. Does the cruise control not engage, not disengage, act erratically?
Please remember that I am not there to test drive it, therefore I rely on you to provide as much detail as possible so that I may accurately diagnose the problem.
Does it surge back and forth between set speed and actual speed, or does it increase in speed and stay there on its own?
They are correct that the cruise control does not engage the braking system as it uses throttle control to increase and decrease speed.
It is considered within specs to be a couple of kph off, either above or below set speed.
But if it is erratic in going above or below set speed on LEVEL ground, there is an issue. It will increase or decrease speed some when traveling up inclines or down hill, so we need to know what it is doing on level roads.
If doing this on level road, that would not be considered normal and is usually caused by a faulty cruise control servo that connects to the throttle body via cable
It is normal to increase speed somewhat when going up an incline and to decrease speed when going downhill, but if it is increasing speed going down a hill instead of using the throttle control to decrease speed, then it is a problem with the servo unit
When going downhill, you should see an initial increase in speed, and then the servo should close the throttle body throat plate to decrease and manage speed to within 1 to 2kph of the set speed, so that at bottom of the hill and flattening out, it should be right at set speed.
A 1 to 2% grade should not be enough to see any significant speed fluctuation. There is definite issue with the servo
They are not my authorized ford dealer. I am an independent shop.
You need to take it to an independent shop to get diagnosed and then take the written diagnosis back to the ford dealer