* Speedometer: This is the most obvious function. The sensor tells the speedometer how fast the vehicle is moving, displaying the speed on the instrument cluster.
* Transmission: The transmission uses the speed sensor's input to determine appropriate shift points for optimal fuel economy and performance. This is vital for automatic transmissions.
* Cruise Control: The cruise control system relies on the speed sensor to maintain a set speed.
* Anti-lock Braking System (ABS): The ABS system uses wheel speed sensors (a type of speed sensor) to monitor wheel speed individually. This allows it to prevent wheel lockup during braking. While not directly the same sensor as the vehicle speed sensor, it's closely related in function.
* Electronic Stability Control (ESC) / Traction Control: Similar to ABS, ESC and traction control systems utilize wheel speed sensors to detect loss of traction and intervene to maintain stability.
* Odometer: The odometer calculates total mileage based on the speed sensor's data.
* Transmission Control Module (TCM): The TCM uses the vehicle speed sensor data to control various aspects of the transmission's operation, such as shift timing and torque converter lockup.
In short, the speed sensor is a vital component for many critical safety and performance systems in the Dodge Ram. A malfunctioning speed sensor can cause a wide range of problems, from an inaccurate speedometer to complete failure of the cruise control or even transmission problems.
