GF07.61-P-3024MAR ME Oxygen Sensor Heater, Function

GF07.61-P-3024MAR ME Oxygen Sensor Heater, Function
- refinement package
- as of model year 09


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. It also prevents ceramic damage to oxygen sensors by means of the controlled heater.

Oxygen sensor heater function sequence
One differentiates between oxygen sensor heaters according to lambda sensor type. The function sequence is therefore described at the following points:
^ Wideband oxygen sensor function sequence
^ Non-linear oxygen sensor function sequence

Wideband oxygen sensor function sequence
The LH and RH O2 sensors upstream of CAT (G3/3, G3/4) are continuously heated when the engine is running, to ensure they function correctly.
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 LH and RH oxygen sensor heaters downstream of CAT (G3/5, G3/6) are actuated and pulsed by the ME-SFI control unit, by means of a ground signal.
The mean pulsed heating current is approx. 400 mA in idle speed range.

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