Circuit Protection

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.

All exterior lighting circuits are protected by Field Effect Transistors (FETs), located in the BCM/GWM assembly, which can detect overloads and short circuits.

The FETs respond to heat generated by increased current flow caused by a short circuit. On a normal circuit this would cause the fuse to blow. The FETs respond to the heat increase and disconnect the supply to the affected circuit. When the fault is rectified or the FET has cooled, the FET will reset and operate the circuit normally. If the fault persists the FET will cycle, disconnecting and reconnecting the power supply. The BCM/GWM assembly stores fault codes which can be retrieved using a Jaguar approved diagnostic system. The fault code will identify that there is a fault on a particular output which assist in fault detection.