Debuting in September 1992 as a 1993 model, the refreshed LS 400 (designed through 1991) was introduced with more than 50 changes, largely in response to customer and dealer requests. The vehicle received larger disc brakes, wheels, and tires, and adjustments were made to the suspension and power steering systems to improve handling. Stylistic changes included additional body side moldings and a revised grille, along with a greater selection of colors. For the interior, a standard passenger front airbag (first Toyota-built series production car available with passenger front airbag), an external temperature gauge, digital odometer, seat belt pretensioners, and chlorofluorocarbon-free refrigerant were added. In 1992, the Celsior introduced the world first GPS navigation system with voice instructions, supplied by Aisin. By 1994, the LS 400's U.S. base price exceeded , a figure that had steadily risen since the vehicle's introduction. Customer demand for the vehicle and shifts in foreign exchange rates contributed to the increase in price. The growing popularity of the LS internationally was an asset to Toyota, as Japan had entered into an economic recession in 1991, that later became what was called the collapse of the Japanese asset price bubble or "bubble economy".