The Readiness Code is a set of 8 bits, each of
which corresponds to one monitored emissions "system" in an OBD-II car. When all
readiness bits show "Passed", it means that all systems have been checked and
have passed
the on-board tests.
VCDS also Decodes Readiness bits into meaningful data
on modern TDI engines (a VCDS exclusive, not even the VAS-5051/5052 does
this!) shown here:
Whenever you clear DTCs, all readiness bits
that are testable will
be set to "Fail". Most cars do not have all 8 systems, so the ECU
should recognize the bits corresponding to systems that are not actually in the car.
These will come up "Passed" automatically without going through any tests.
It takes a variety of
specific driving conditions to "test" all the systems. In practice, driving
a properly-functioning car for 2-3 days including at least one short highway
trip, should be sufficient to test each of the Readiness Bits to set all of
the testable ones to "Pass". It can be done in a short time
using a very specific and complicated procedure found in the On Board Diagnostic
section of the Factory Repair Manual for your engine or you can use the Guided
Readiness Script function in VCDS as described below.
Click on
[Save] to store the results to your PC, typically
in this directory:
C:\Ross-Tech\VCDS\Logs
Use [Go
Back] to return to the Controller Information Screen.
The
Guided Readiness Scripts function will guide the user
through the process of setting Readiness on those engines which support it by
clicking on the [Set
Readiness] button. The button will be grayed out if Readiness bits
are already set (you can clear fault codes to un-set them) or if appropriate
documentation does not exist in VCDS for that specific ECU.
