Motronic ME 7
Heated Oxygen Sensor (HO2S) G39 and Heated Oxygen Sensor (HO2S) 2 G108
A broadband oxygen sensor is assigned to each
precatalytic converter as a pre-catalytic oxygen
Broadband Oxygen Sensor
sensor.
Using the broadband oxygen sensors, a wide range
of oxygen concentration in the exhaust gas can be
calculated. Both oxygen sensors are heated to reach
operating temperature more quickly.
Signal Utilization
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The signals from the Heated Oxygen Sensors are
one of the variables used in calculating the injection
Effects of Signal Failure
timing.
If the pre-catalytic converter oxygen sensor fails,
there is no closed loop control. The fuel injection
adaptation is not available. An emergency running
mode is enabled using an engine characteristics map.
Oxygen Sensor (O2S) BehindThreeWay Catalytic Converter (TWC) G130 and
Oxygen Sensor (O2S) 2 BehindThreeWay Catalytic Converter (TWC) G131
The planar oxygen sensors are located downstream
Planar Oxygen Sensor
of the pre-catalytic converter. They measure the
remaining oxygen content in the exhaust gas. Based
on the amount of oxygen remaining in the exhaust
gas, the ECM can draw conclusions about the
catalytic converter operation.
Signal Utilization
The ECM uses the signals from the post-catalytic
converter oxygen sensors to check the catalytic
converter operation and the closed-loop oxygen
control system.
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Effects of Signal Failure
If the post-catalytic converter oxygen sensor fails, the
closed loop operation continues. The operation of the
catalytic converter can no longer be checked.
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