Ranking Values
There are ranking values for each diagnostic trouble code (DTC). A ranking value is a counter that indicates how close to storing a diagnostic trouble code (DTC) the system considers itself to be for each diagnostic function, in relation to a component or function. The counter counts upwards when the fault is active and downwards when the fault is not active (A).
When the ranking value exceeds a certain level, normally 128, a reconfiguration is performed where substitute values are activated in the system (B).
HINT: Read more about the substitute values for the diagnostic trouble codes (DTCs) in the Information Manager, under each the information for each diagnostic trouble code (DTC).
When the ranking value exceeds a further level, normally 255, a diagnostic trouble code (DTC) is stored (C).
HINT: For certain functions, a diagnostic trouble code (DTC) is stored at the same time as the substitute value is activated, i. e. at ranking value 128. For other functions the counter continues to 255 before a diagnostic trouble code (DTC) is stored.
The ranking information consists of two values:
- "Latest" indicates the ranking value at read out
- "Worst" indicates the highest ranking value the diagnostic trouble code (DTC) has reached.
These parameters are reset when diagnostic trouble codes (DTCs) are erased or when the power is to the control module is cut.
HINT: By comparing "Latest" with "Worst", it is often possible to determine whether the fault is permanent or intermittent. Low "Latest" and high "Worst" indicates an intermittent fault.