ME-SFI two-sensor control - function - GF07.61-P-3020SM

ENGINE 113.986 

ENGINE 113.987 

ENGINE 113.988 

ENGINE 113.989 

Fig 1: ME-SFI Two-Sensor Control - Function (Engine 113)

The ME engine control unit (N3/10) determines the lambda mean value based on O₂ sensor signals downstream of the TWC. This value is compared with a stored value for optimum exhaust emissions.

If the deviation is too large after a number of measurements, a correction variable (delay time) is determined for the lambda control.

The correction variable (value for new O₂ sensor upstream TWC approx. 0) makes it possible to compensate for aging of the O₂ sensors upstream of TWC within certain limits. If the correction variable exceeds the limit value, the O₂ sensors upstream of the TWC must be replaced.

The correction values are map-controlled and are implemented by the ME control unit by adapting the fuel injection.

If the limits are exceed or there is a negative plausibility check for the O₂ sensor signals, the engine diagnosis indicator lamp (A1e58) or the "CHECK ENGINE" MIL (A1e26) next to the instrument cluster (A1) lights up.

Any exceeding of the limit value is recorded in the fault memory and can be read out using the STAR DIAGNOSIS and then deleted.

The O₂ sensor signals downstream of the TWC allow monitoring of the effect of the firewall catalytic converters (157).

	Component description for the fuel injection valves	Y62		GF07.03-P-6010SM
	Component description for the O2 sensors	G3/3, G3/4, G3/5, G3/6		GF07.04-P-6100SM
	Component description for the ME-SFI [ME] control unit	N3/10		GF07.61-P-6000SM
	Component description for the exhaust system			GF49.00-P-3010SM
	Component description for the three-way catalytic converter	157, 158		GF49.10-P-2010SM
	Component description for the engine diagnosis indicator lamp	A1e58	Except	GF54.30-P-5010SM
	"CHECK ENGINE" MIL Component description for "CHECK ENGINE" MIL	A1e26	At	GF54.30-P-5011SM