Direct Digital Lambda (DDL)
Wide-Band Exhaust-Gas-Oxygen Sensor

Copyright © 2000, 2001 Bernd Felsche , Perth, Western Australia.

A Wide-Band O2 Sensor

The Bosch wide-band sensor (LSU) and the NTK/NGK wideband sensor is actually comprised of four distinct sections:
  • Reference Cell
  • Nernst Cell
  • Pump Cell
  • Heater

Very little hard, detailed information about how the sensors are supposed to be driven is readily available. The pump cell current required to maintain a relative voltage output of 0.45V between the measurement cell and the reference cell, is a measure of lamba, the fuel-air ratio.

An integrated heating element is used to maintain a minimum cell operating temperature of 600 C. Upper temperature limit is typically 800 C. A stable sensor temperature is desirable as it's characteristics vary significantly with temperature.

Any data referred to herein are based on the following references
and should not be applied to any other type of sensor.

References (German):

  • Bosch: Kraftfahr Technisches Taschenbuch 22. Auflage 1998
    ISBN 3-540-62219-5
  • Bosch: Ottomotor-Management 1. Auflage 1999
    ISBN 3-528-03877-2

English equivalents

  • Bosch: Automotive Handbook 5th Ed. 2000
    ISBN 0-7680-0669-4
  • Bosch: Gasoline Engine Management 1st Ed. 1999
    (the author has not seen this book) ISBN 0-7680-0510-8
Bosch Illustration
Illustration from (German) Bosch Automotive Handbook have some data including:


Copyright © 2000 Bernd Felsche , Perth, Western Australia.