For model year 1999 a minor facelift was introduced. Apart from very minor cosmetic changes, such as a slightly different Volvo badge on the front grille and US models now being equipped with side markers on the front fenders, most changes were done to the mechanicals. Volvo introduced its second generation side airbag which increased in volume to offer better protection. WHIPS, Volvo's system to minimize whiplash injuries, was also introduced as part of the standard equipment. New engine management systems with drive-by-wire replaced the mechanical throttle on all turbo engines as well as bringing with them an upgraded traction control. Now including throttle as well as brake intervention it was renamed "STC". The ABS was upgraded from a three-channel to a four-channel system, all-wheel drive models received thicker rear discs and redesigned rear calipers. All automatic transmissions were now equipped with adaptive shift-logic, replacing the previous 3-mode selection. A starter interlock was added to models with manual transmissions.