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

ENGINE 275.953 in MODEL 216.376, 221.176 as of Model Year 09/AEJ 08 

ENGINE 275.982 in MODEL 216.379, 221.179 as of Model Year 09/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.

To control the oxygen sensor heaters, the ME-SFI control unit (N3/10) reads the coolant temperature sensor (B11/4).

Oxygen sensor heater function sequence 

Using a ground signal, the ME-SFI control unit actuates and synchronizes the oxygen sensor heaters of the LH and RH O₂ sensors upstream of the CAT (G3/3, G3/4) and the LH and RH O₂ sensors downstream of the CAT (G3/5, G3/6).

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 216	PE07.61-P-2766-97CAA
		Model 221	PE07.61-P-2766-97SAA
	ME-SFI [ME] control unit, component description	N3/10	GF07.61-P-6000MOS