Speed Dependent Damping Control (also called SD²C) was an automatic damper

Shock absorber

A shock absorber is a mechanical device designed to smooth out or damp shock impulse, and dissipate kinetic energy. It is a type of dashpot.-Nomenclature:...

 system installed on late-1980s and early-1990s Cadillac

Cadillac

Cadillac is an American luxury vehicle marque owned by General Motors . Cadillac vehicles are sold in over 50 countries and territories, but mostly in North America. Cadillac is currently the second oldest American automobile manufacturer behind fellow GM marque Buick and is among the oldest...

 automobile

Automobile

An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

s. This system firmed up the suspension at 25 mph (40 km/h) and again at 60 mph (97 km/h). The firmest setting was also used when starting from a standstill until 5 mph (8 km/h).

Applications:

• 1989–1992 Cadillac Allanté
  Cadillac Allanté
  The Allanté was Cadillac's first venture into the ultra-luxury roadster market. The vehicle was sold from 1987 until 1993, with roughly 21,000 models built over its 7-year production run...
  
  

Computer Command Ride

The system was updated as Computer Command Ride in 1991. This new system included acceleration, braking rates, and lateral acceleration to the existing vehicle speed metric.

• 1991– Cadillac Fleetwood
  Cadillac Fleetwood
  Lawrence P. Fisher was the Fisher brother most closely involved with Cadillac in its early years. In 1916 he joined the Fisher Body Company which had been formed by two of his brothers in 1908. Larry was one of four of the seven Fisher brothers who brought Fisher Body Corporation under the General...
  
  
• 1991– Cadillac Eldorado
  Cadillac Eldorado
  The 1953 Eldorado was a special-bodied, low-production convertible . It was the production version of the 1952 El Dorado "Golden Anniversary" concept car, and borrowed bumper bullets from the 1951 GM Le Sabre show car...
  
  
• 1991– Cadillac Seville
  Cadillac Seville
  The Cadillac Seville is a luxury-type car that was manufactured by the Cadillac division of American automaker General Motors from 1975 to 2004, as a smaller-sized top-of-the-line Cadillac...
  
  
• 1991– Cadillac De Ville (optional, standard for 1993)