...the ECM also is learning about the amount of fuel correction that it is making. This learned value is used by the ECM during both open- and closed-loop operations to help fine tune the fuel control for each particular engine and its operating conditions.
Each time the ECM is disconnected or the EFI fuse is removed, the ECM will also lose its learned value stored in memory. For the ECM to relearn the value, the vehicle must be driven in closed-loop, feedback operation for a certain amount of time. The amount of time will vary depending on the engine and the type of conditions the vehicle is driven in.
