Possible Causes

WARNING: This page is about a different car, the 2017 Jaguar XJ, 2016 Jaguar XJ, 2015 Jaguar XJ, 2014 Jaguar XJ, and 2013 Jaguar XJ. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Monitor description . Detects when secondary fuelling adaptation offset is too large for fuel mixture control to be maintained

Exhaust system leakage
Post catalyst oxygen sensor incorrectly installed or harness failure
Pre catalyst oxygen sensor incorrectly installed or harness failure
Post catalyst oxygen sensor damaged or contaminated internally
Pre catalyst oxygen sensor damaged or contaminated internally
Post catalyst oxygen sensor failure
Pre catalyst oxygen sensor failure