ME oxygen sensor heater, function - GF07.61-P-3024MAS
ENGINE 156.984 in MODEL 216.377, 221.077 /177 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 (O 2 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 described in the following steps:
- Wideband oxygen sensor function sequence
- Non-linear oxygen sensor function sequence
Wideband oxygen sensor function sequence
The LH and RH O 2 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 oxygen sensor heaters of the LH and RH O 2 sensors downstream of the CAT (G3/5, G3/6) are actuated and pulsed 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 216 | PE07.61-P-2766-97CAC | |
| Model 221 | PE07.61-P-2766-97SAC | ||
| ME-SFI [ME] control unit, component description | N3/10 | GF07.61-P-6000MAS |