When the 1000 Series is used in GM HD pickups or Chassis Cabs, two features come into play:
 

• Automatic grade-braking helps the driver slow the vehicle and avoid excessive use of the brakes when hauling or pulling heavy loads down long, steep grades.
   
  • When drivers carrying heavy loads encounter a steep hill, they can manually shift into a lower gear for added engine braking to slow the truck.
     
    
  • The 1000 Series collects operating data, including how long the driver's foot has been on the brake, vehicle speed, gear currently engaged, etc., and uses it to calculate shift parameters.
     
    
  • At a certain threshold, the Trans Control Module (TCM) of the 1000 Series will cause the transmission to downshift without the driver having to move the gear lever. Manual range selection is still available to the driver.
     
    
• Shift stabilization uses the same type of advanced logic.
   
  • This feature detects and overcomes "shift busyness" that might be found in mountainous or hilly terrain.
     
    
  • Algorithms housed in the TCM analyze the conditions, and when the parameters are satisfied, the transmission is maintained in the lower gear for optimal performance.
     
    
  • The stabilizing effect this has makes driving a loaded vehicle considerably more comfortable