Diesel Exhaust Fluid (Def) Quality: Notes

WARNING: This page is about a different car, the 2018 Jaguar XE and 2017 Jaguar XE. However, it is still accessible from the selected car via links, so may be relevant.

The DEF quality is monitored after refilling of the DEF tank. The monitoring begins when refilling is identified. In order to recognize a poor quality DEF, the OBD system uses the SCR catalytic converter NOx efficiencies, returned by the passive SCR catalytic converter monitoring, to build long and short term records of the average NOx conversion efficiencies. If the short term record becomes significantly different to the long term record, the malfunction is attributed to the quality of the DEF. The message center warning system is activated when such a malfunction is detected. Simultaneously, the MIL is directly activated on the first occurrence of the malfunction detection

STAGES	CAUSE	WARNING	MESSAGE	DESCRIPTION
Stage 1	Incorrect DEF quality is detected	Amber symbol	Incorrect Diesel Exhaust Fluid quality detected	The DEF does not meet manufacturer specifications. The system must be checked by a Jaguar Land Rover service department
Stage 2	Incorrect DEF quality is detected	Amber symbol	No engine restart possible in 515mls/830km. Incorrect Diesel Exhaust Fluid quality detected	The DEF does not meet manufacturer specifications. The system must be checked by a Jaguar Land Rover service department
Stage 3	Incorrect DEF quality is detected	Amber symbol	No engine restart possible soon. Incorrect Diesel Exhaust Fluid quality detected	The DEF does not meet manufacturer specifications. The system must be checked by a Jaguar Land Rover service department
Stage 4	Incorrect DEF quality is detected	Red symbol	No engine restart possible. Incorrect Diesel Exhaust Fluid quality detected	The DEF does not meet manufacturer specifications. The system must be checked by a Jaguar Land Rover service department