View source for WIS 07.61 Gasoline Engine and Injection System ME

'''Heated Oxygen O2 Sensors (Lambda Sensors)'''

http://w220.ee/images/b/b7/W220_O2_Heated_Oxygen_Sensors.JPG

'''Heated Oxygen O2 Sensors How It Works'''

The Heated Oxygen Sensor (H2OS) or Lambda Sensor produces a voltage from approximately 1.0V during rich operating conditions to 0.01V (100mV) during lean conditions. The H2OS is like an open circuit and produces no voltage when it is below 360C (600F).

The powertrain control module (PCM) supplies a bias voltage of about 450 mV between the heated oxygen sensor (HO2S) high signal and low signal circuits.  The oxygen sensor (O2S) varies the voltage within a range of about 1,000 mV when the exhaust is rich, down through about 10 mV when exhaust is lean. The PCM constantly monitors the HO2S signal during Closed Loop operation and compensates for a rich or lean condition by decreasing or increasing injector pulse width as necessary. If the HO2S voltage remains at or near the 450 mV bias for an extended period of time, P0154 diagnostic trouble code (DTC) will be set.

'''Heated Oxygen O2 Sensor Fault Codes'''

* P20BF-004 G3/3 Left O2 sensor before TWC (KAT) open circuit in sensor heater line (P0156)
* P2082-004 G3/3 Left O2 sensor before TWC (KAT) open circuit (P0154)

'''Heated Oxygen O2 Sensor Cable Lengths'''

Note two different lengths.

* Front or Upstream Left/Right (Long Cable)
* Rear or Downstream Left/Right (Short Cable)

http://w220.ee/images/1/1f/W220_Heated_Oxygen_Sensors_Front_or_Upstream_%28Long_Cable%29_Rear_or_Downstream_%28Short_Cable%29.JPG

'''Heated Oxygen O2 Sensor Connector Pin Diagram'''

http://w220.ee/images/a/a2/O2_Sensor_Connector_Pin_Diagram.JPG

S500 OEM Connector to Sensor Cable Wire Colours
* Pin 1 White Heater
* Pin 2 White Heater
* Pin 3 Grey O2 Sensor Low
* Pin 4 Black O2 Sensor High

S500 OEM Connector to Car Cable Wire Colours
* Pin 1 Red Heater Ground
* Pin 2 Brown Heater +12V
* Pin 3 Green O2 Sensor Low
* Pin 4 Black O2 Sensor High

'''Heated Oxygen O2 Sensors DIY Articles'''

http://www.benzworld.org/forums/w203-c-class/1474361-p0154-code-wont-go-away.html

http://www.benzworld.org/forums/w203-c-class/1474361-p0154-code-wont-go-away-2.html

http://www.hotrodlane.cc/New%20LS%20Links%20Page/LS%20trouble%20codes/DTC%20P0154.htm