Additive adaptation
If closed loop continuously corrects a deviation in the fuel system, it will be adapted. Adaptation occurs every 5 minutes and takes 30 seconds. The additive adaptation, which is 0.000 mg fuel/combustion when the control module is new or has been disconnected, is always added to the fuel quantity. The additive adaptation takes place at idling speed. Purging is stopped during adaptation because other factors that can affect the fuel must not be active.
The fuel quantity is added or subtracted until closed loop fluctuates around 1.00 (0%). Additive adaptation is required because air leaks at idling speed will lead to a greater fault that must not be adapted multiplicatively as the fuel quantity would then be far too great when the load was increased.
The limits for the additive adaptation are minus 4 and 4 mg fuel/combustion respectively.
A multiplicative adaptation must always take place before an additive after starting the engine.
The following conditions must be fulfilled for additive adaptation to take place:
- Closed loop active.
- No purging may occur; this takes place for 4 minutes and 30 seconds every 5-minute period.
- Engine coolant temperature exceeds 76°C.
- Engine speed 750-950 RPM.
- Engine load 85-230 mg/c.
- Car stationary.