If the cruise control is of the vacuum operated type the problem may be very low manifold vacuum until the engine gets hot.
Check for proper manifold vacuum with proper vacuum gauge if the reading is lower than 20-21 at engine idle there is a vacuum leak somewhere, which is also having a negative affect on fuel economy. If no leak if found externally, you may have an engine in need of a valve job.
its setting a code
Yes it could, if it is setting codes it will affect the cruise.
Cruise will NOT work if the speedometer has a problem
Fuse
check the setting on the cruise control check the setting on the cruise control check the air flow meter is ok
The air blower and the cruise control are completely powered by separate fuses. It is possible that both have blown fuses.
Check the fuse first.
Blown fuseA short in the cruise control circuit,Faulty brake or clutch switch,Leaking vacuum circuit,Faulty cruise switch,faulty stepper motor,faulty transducer,faulty speed sensor,faulty cruise control module.That help a little?
It is important to know the meaning of flashing lights in a car. When the cruise control set light flashes, it either means the driver hasn't finish setting the control, or that there is an issue with the fuse or wiring.
If the car is going up an incline, it will attempt to keep the speed constant with the setting of the cruise control. When that process is satisfied, the car may decelerate a bit to keep the same speed. If the car continually decelerates whe using the cruise control. stop using the cruise and have it checked. It id very dangerous to use the cruise control that is not operating properly. It could cause the car to accelerate unexpectedly.
It is probably the cruise control actuator cable. The actuator is what, through the commands of the cruise control system and driver imputs, determin a speed setting
You need to have it checked for trouble codes. You can then diagnose the cause.