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Multiplicative 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.

Fig 1: Identifying Multiplicative Adaptation Graph
G03708769Courtesy of SAAB-SCANIA OF AMERICA, INC.
Fig 2: Identifying Multiplicative Adaptation
G03708770Courtesy of SAAB-SCANIA OF AMERICA, INC.

The fuel quantity is always multiplied by a multiplicative adaptation factor of 1.00 when the control module is new or has been disconnected. Multiplicative adaptation takes place under conditions of partial load. Purging is stopped during adaptation because other factors that can affect the fuel must not be active.

The entire closed loop deviation from 1.00 is transferred to the multiplicative adaptation factor. This means that the correct fuel quantity will be injected even when closed loop is inactive, e.g. when cold starting or driving under full load. A multiplicative adaptation must always take place before an additive after starting the engine. Limits for multiplicative adaptation are 0.75 and 1.25 respectively.

The following conditions must be fulfilled for multiplicative adaptation to take place:

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 fuel quantity is always multiplied by a multiplicative adaptation factor of 1.00 when the control module is new or has been disconnected. Multiplicative adaptation takes place under conditions of partial load. Purging is stopped during adaptation because other factors that can affect the fuel must not be active.

The entire closed loop deviation from 1.00 is transferred to the multiplicative adaptation factor.

This means that the correct fuel quantity will be injected even when closed loop is inactive, e.g. when cold starting or driving under full load. A multiplicative adaptation must always take place before an additive after starting the engine. Limits for multiplicative adaptation are 0.75 and 1.25 respectively.

The following conditions must be fulfilled for multiplicative adaptation to take place: