Deceleration Fuel Injection Shutoff
WARNING: This page is about a different car, the 1992 Mercedes-Benz 400E. However, it is still accessible from the selected car via links, so may be relevant.
When vehicle is decelerating with throttle valve in idle position and engine coolant temperature is greater than 158°F (70°C), fuel injection is shut off in 2 stages, depending on whether engine speed increases or decreases during deceleration.
In the first stage, half of the fuel injectors are turned off. In the second stage, all fuel injectors are turned off. When coolant temperature is less than 68°F (20°C), deceleration shutoff is canceled.