Deceleration Fuel Cut

The Deceleration Fuel Cut module controls the deceleration fuel cut off (DFCO) feature. When this feature is activated, the module cuts off all fuel by switching off the injectors. In theory, this improves fuel economy by allowing the vehicle to coast on its momentum rather than burning fuel while decelerating.

The feature is enabled when all of the following conditions are met:

￭

Deceleration Fuel Cut Enabled is TRUE.

￭

The engine speed is greater than or equal to Deceleration Fuel Cut Enable Engine Speed Minimum.

￭

The engine coolant temperature is greater than or equal to Deceleration Fuel Cut Enable Engine Coolant Temperature Minimum.

￭

The engine isn't idling. (Idle Active is FALSE).

Once all four of these conditions are met, the feature begins watching for the following additional conditions. These conditions must be met to switch off the injectors:

￭

The measured throttle position is less than the value specified in Deceleration Fuel Cut Enable Throttle Position.

￭

The measured manifold absolute pressure falls below the value specified in Deceleration Fuel Cut Entry Enable MAP.

The feature will then be "active" (Deceleration Fuel Cut Active = TRUE). The injectors will be switched off after the amount of time specified in Deceleration Fuel Cut Delay.

This feature is deactivated (and the injectors are turned back on) when MAP rises to the level specified in Deceleration Fuel Cut Exit Enable MAP.