* If your trailer has electric brakes: Yes, you absolutely need an electronic brake controller. The controller allows you to activate the trailer's brakes proportionally to your Dakota's braking, preventing jackknifing and ensuring safe stopping.
* If your trailer does NOT have electric brakes: No, you don't need a brake controller. However, you might need a 7-way or 4-way wiring harness depending on the trailer's lighting system.
Consult your owner's manual for your Dakota and your trailer's owner's manual for weight ratings. If the combined weight of your truck and trailer exceeds a certain threshold (this varies by state and local regulations, but is typically around 10,000 lbs, check your local DMV) you'll likely be required by law to have trailer brakes.
In short, the tow package only provides the wiring; it doesn't automatically include a brake controller. The need for a brake controller is determined by the trailer's braking system.
