A hill problem usually arrives as a moment rather than a fault message. The car hesitates when you ask it to pull away from a stop on a grade, or it seems to creep backward before the engine takes hold. Before you compare model lines to solve it, separate what the car is doing from what the driver feels.
Name the sequence, not the cause
Write down the order of events. Note whether the car was stopped on the slope, which foot was on which pedal, how long the brake was held, and whether the gear selector was in drive or reverse. A delayed response after the throttle is a different problem from a car that moves when the brake is released. Each has its own check, and the two are easy to confuse from memory.
Log the conditions that repeat
Keep a short note for each episode: the steepness of the grade, the load in the car, the outside temperature, and whether the engine was warm. A pattern across several episodes tells you more than a single bad start. If the pattern appears only with a trailer or a full load, the load may be the variable that matters.
Check whether the feature is listed for your trim
Some model lines list a hill hold or hill descent feature on certain trims and not others. Open the model-year row for the line and read the trim's feature list before you assume a missing function is a fault. A feature that was never fitted to your trim cannot be repaired into the car.
When the car moves on a grade
If the car rolls or moves unexpectedly on a slope, stop using that slope with it until a qualified technician has looked at it. Do not treat the brake or the hold feature as a substitute for a check. The owner's manual describes the intended operation, and a dealer or independent shop can test it under your conditions.