GF07.61-P-4022BK ME-SFI Lambda Control, Function

GF07.61-P-4022BK ME-SFI Lambda Control, Function







The mixture composition is maintained within limits as close as possible to (Lambda)=1 in order to achieve a high conversion of the exhaust gases in the catalytic converter.

The O2 sensors upstream of the catalytic converter the oxygen concentration in the exhaust and transmit corresponding signals to the ME-SFI [ME] control unit. This changes the mixture composition so that in all engine operating statuses, the desired oxygen (usually (Lambda) =1) is set.

This procedure is repeated (control loop), the control speed is dependent on engine load and speed.

The lambda closed-loop control is operational in the following operating conditions (closed-loop control):
- Coolant temperature > approx. -10 °C,
- Blocking time after starting expired
- O2 sensors upstream CAT have reached operating temperature















Lambda control loop
Assuming a leaner air/fuel mixture is produced. The consequence of this is that the O2 sensor voltage drops and the ME-SFI [ME] control unit compensates for this lean drift by enriching the mixture accordingly.

This makes it possible to achieve an air/fuel composition of approximately (Lambda)=1. The reading of the lambda control factor with the STAR DIAGNOSIS moves towards +25 % The more the lambda control factor moves towards +25 %, the leaner is the air/fuel mixture and the greater is the enrichment of the mixture on the part of the ME-SFI [ME] control unit.