GF07.04-P-6104MIK Component Description For A O2 Sensor Upstream of CAT

GF07.04-P-6104MIK Component Description For A O2 Sensor Upstream Of CAT
- refinement package
- as of model year 09

Component Identification:

Location
The O2 sensors upstream of CAT are screwed into the exhaust pipes in front of the firewall catalytic converters.

Task
The O2 sensors upstream of CAT (control sensors) detect the residual oxygen content in exhaust gas for the following tasks:
- Lambda control
- Self-adjustment of mixture formation
- Function chain tests (for OBD II or EOBD)

Design

Component Identification:

The O2 sensor upstream of CAT is designed as an insulated potential-free and planar (flat) wideband oxygen sensor
The active sensor ceramic consists of a gas permeable ceramic body made of zirconium dioxide. The inner protective tube with several slots protects the ceramic body from mechanical stresses and from temperature jumps.

Component Identification:

The balance resistor (6) is dependent on the overall length (L) and on the type of sensor.

Function
The sensor element consists of a combination of a Nernst concentration cell (sensor cell) and an oxygen pump cell which transports (pumps) the oxygen ions.
The pump action is a purely physical process.

In combination with the control electronics integrated with the ME-SFI control unit (N3/10), the wideband oxygen sensor is able to measure accurately over a large lambda range ( Lamda0.7 to 4.0).

While changing the wideband oxygen sensor, the balance resistor is already fitted on the new sensor and must not be changed (resistance depends on the sensor).

Oxygen sensor heater
The integrated oxygen sensor heaters ensure the required operating temperature of about 750 °C. In order achieve the sensor function while the engine is running, wideband oxygen sensors are heated constantly with a heat output of about 10 W.

The oxygen sensor heaters are actuated by the ME-SFI control unit with a ground signal.
The voltage supply takes place from "circuit 87 M2".