O2 sensor heater, function - GF07.61-P-3025CY

ENGINE 272.911 in MODEL 204.0 up to Model Year 08 

ENGINE 272.921 in MODEL 204.0/2 up to Model Year 08 

ENGINE 272.947 in MODEL 204.0/2 up to Model Year 08 

ENGINE 272.948 in MODEL 204.0 up to Model Year 08 

ENGINE 272.961 in MODEL 204.0/2 up to Model Year 08 

ENGINE 272.971 in MODEL 204.0 up to Model Year 08 

The oxygen sensor heaters bring the oxygen sensors more rapidly up to operating temperature. They also avoid ceramic damage to oxygen sensors through controlled heating.

Oxygen sensor on the left and right upstream of the catalytic converter (G3/3, G3/4) (wideband oxygen sensor) 

The oxygen sensor is heated constantly when the engine is operated in order to ensure proper function.

Temperature control and temperature measurement (by measuring the internal resistance) (N3/10) performed by special control electronics in the ME-SFI [ME] control unit.

Oxygen sensor on the left and right downstream of the catalytic converter (G3/5, G3/6) (voltage jump oxygen sensor) 

The oxygen sensor heaters are actuated and pulsed by the ME-SFI [ME] control unit via a ground signal. The mean pulsed heating current is approx. 400 mA in idle speed range. The current in the cold state is increased approximately by the factor 4.

The sensor heaters are switched off at coolant temperatures below approx. 20°C and at high engine speeds to protect the sensor ceramics.

Power supply to oxygen sensor heaters takes place via "circuit 87 M" from the ME-SFI [ME] control unit.

	Electrical function diagram, oxygen sensor heating			PE07.61-P-2766-99FAB
	Component description for the coolant temperature sensor	B11/4		GF07.04-P-6043CY
	Component description for the oxygen sensor	G3/3, G3/4	Oxygen sensor upstream of TWC [KAT]	GF07.04-P-6101CY
		G3/5, G3/6	Oxygen sensor downstream of TWC [KAT]	GF07.04-P-6101CZ
	Component description for the crankshaft Hall sensor	B70		GF07.04-P-6221CY
	Component description for the ME-SFI [ME] control unit	N3/10		GF07.61-P-6000CY