Oil Ash Residue.

[dlloyduk]

How is this reading obtained and reset. After recent oil change and service I would have expected some change. Reading is not changed?

[admin]

This is not directly related to the engine oil. This is a residue coming from the fuel combustion and it isn't removable, in fact when this deposit reaches the maximum accepted value, the filter must be replaced.
Only in this case, using a diagnostic tester, the oil ash value can be reset to 0 corresponding to the new filter installation.