Electronic Engine Controls - System Operation And Component Description (G1791748): Diagnostics
WARNING: This page is about a different car, the 2015 Jaguar XF, 2014 Jaguar XF, and 2013 Jaguar XF. However, it is still accessible from the selected car via links, so may be relevant.
The ECM stores each fault as a DTC (Diagnostic Trouble Code). The DTC and associated environmental and freeze frame data can be read using Jaguar approved diagnostic equipment, which can also read real time data from each sensor, the adaption values currently being employed and the current fueling, ignition and idle speed settings.