Technical Description: Compensation: Knocking

WARNING: This page is about a different car, the 2001 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Workflow Diagram - Mass Air Flow Sensor (Knocking)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 2: Correction Factor Graph (Knocking)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

If the engine is knocking, it is corrected by retarding the ignition for the cylinder in question. If knocking persists despite the retardation, the correction factor will be increased. Closed loop will then be deactivated (if it was active) as it would otherwise counter-compensate.