ECM LambdaCAN Series, Instruction Manual

Page: 10 / 50

6
 Delta O2 Table and Delta Lambda Table
The %O2 calculated by LambdaCAN* modules is denoted as “O2R” and is a wet (i.e. water
taken into consideration in %O2 calculation), at chemical-equilibrium (i.e. not frozen-
equilibrium) %O2 measurement (see Appendix D). The Lambda (AFR, FAR, PHI)
calculated by LambdaCAN* modules is denoted as “LAMR” and matches that calculated by
mass flowrates of air and fuel entering the engine.
Sometimes users would like dry %O2 readings, or frozen-equilibrium %O2 readings, or dry
frozen-equilibrium readings, or readings that match another instrument. For this purpose, the
Delta O2 Table is used. The Delta O2 Table (found in the task “Lambda/O2 Delta Tables”)
allows the user to add a number (a “delta”) to the “O2R” calculated by the LambdaCAN*
module giving the “O2” parameter:
O2 = O2R + Delta O2 Table value (interpolated from table)*
* except when O2R > 18 for which O2 = O2R, regardless of table data.
A Delta O2 Table can be created, edited, and saved as a text file (.txt) on your PC. The file
must be downloaded into the LambdaCAN* module for it to be used. Unlike the sensor
calibration information (i.e. span) which is stored in a memory chip in the sensor’s connector,
the Delta O2 Table is stored in the module.