ME oxygen sensor heater, function - GF07.61-P-3024MIG

ENGINE 272.945 in MODEL 251.054/154 as of Model Year 2009/AEJ 08 

ENGINE 272.967 in MODEL 164.186 as of Model Year 2009/AEJ 08 MOPF 

ENGINE 272.967 in MODEL 251.056/065/156/165 as of Model Year 2009/AEJ 08 

ENGINE 273.923 in MODEL 164.871 as of Model Year 2009/AEJ 08 

ENGINE 273.963 in MODEL 164.172 as of Model Year 2009/AEJ 08 MOPF 

ENGINE 273.963 in MODEL 164.886, 251.072/172 as of Model Year 2009/AEJ 08 

Function requirements for oxygen sensor heater, general points 

• Circuit 87M ON (engine control ON)
• Engine running

Oxygen sensor heater, general points 

The oxygen sensor heaters bring the oxygen sensors (O₂ sensors) up to operating temperature more rapidly. With controlled heating, they also prevent damage to the oxygen sensor ceramics.

Oxygen sensor heater function sequence 

The oxygen sensor heaters differ according to lambda sensor type.

The function sequence is described in the following steps:

• Wideband oxygen sensor function sequence 
• Non-linear oxygen sensor function sequence 

Wideband oxygen sensor function sequence 

The O₂ sensor on the left and right upstream of CAT (G3/3, G3/4) are constantly heated while the engine is running to achieve their function. Temperature control and temperature measurement (by measuring the internal resistance) is performed by special control electronics in the ME-SFI [ME] control unit (N3/10)

Non-linear oxygen sensor function sequence 

The oxygen sensor heaters for the LH and RH O₂ sensors downstream of the CAT (G3/5, G3/6) are actuated by the ME-SFI control unit with a ground signal.

To do this, the ME-SFI control unit (N3/10) reads the signal from the coolant temperature sensor (B11/4).

When the exhaust system is very cold (while condensation is present), the oxygen sensor heaters are switched off to prevent damage (due to thermal shock).

	Electrical function schematic, oxygen sensor heating ME	Model 164		PE07.61-P-2766-97MAA
		Model 251		PE07.61-P-2766-97RAA
	ME-SFI [ME] control unit, component description	N3/10	Engine 272	GF07.61-P-6000MIG
		N3/10	Engine 273	GF07.61-P-6000MLG