Closed Loop Lambda Control - Enable conditions

Closed loop lambda control is enabled (with a delay) at the start of a driving cycle and can be temporary or permanently deactivated during the driving cycle. The turn-on delay at the start of a driving cycle is described by the following enable conditions:

• the upstream oxygen sensor operability is detected i.e. the upstream HO2'S operating temperature has been reached
• a calibrated delay time, after end of engine start, has elapsed

Only for linear Lambda Sensor - Disable conditions 

• the A/F ratio set-point value lies below oxygen sensor's measurable limit

Closed loop lambda operation is further deactivated during a driving cycle when any of the following conditions are fulfilled:

• during fuel cut-off or cylinder shut-off and immediately afterwards till a calibrated integrated mass air flow threshold is exceeded
• the mass air flow is below a calibrated threshold that leads to the minimum possible injection time