GF07.61-P-3025KE O2 Sensor Heater, Function

GF07.61-P-3025KE O2 Sensor Heater, Function
- up to model year 08

Component Identification:

The purpose of the O2 sensor heater is to rapidly heat up the O2 sensors to their operating temperature while preventing damage to the sensor ceramic as a result of controlled heating.

O2 sensor upstream of TWC (broadband oxygen sensor)
The O2 sensor is heated continuously during engine operation, to guarantee its function.
The temperature control and temperature measurement (by measuring the internal resistance) is performed by special control electronics in the ME-SFI [ME] control unit.

O2 sensor downstream TWC
The O2 sensor heater is 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 heater is switched off at coolant temperatures below approx. 20 °C and at high engine speeds as a protection for the sensor ceramic.

Voltage supply to the O2 sensor heater takes place over the ME control unit from the front SAM control unit with fuse and relay module/driver.