Introduction

Introduction

Vehicle Identification Numbers (VIN)
VIN ranges are presented throughout in the following manner:
--> VIN 123456 indicates "up to VIN 123456"; VIN 123456 --> indicates "from VIN 123456 on".

Jaguar 2003.5 Model Year XJ Electrical System Architecture

Power Supplies
The Jaguar 2003.5 Model Year XJ electrical system is a supply-side switched system. The ignition switch directly carries much of the ignition switched power supply load. Power supply is provided via three methods: direct battery power supply, ignition switched power supply, and "Switched System Power Supply". The "Switched System Power Supply" circuit is controlled via the FEM ((Front Electronic Module) and the REM (Rear Electronic Module).

Fuse Boxes
The electrical harness incorporates three serviceable power distribution fuse boxes: the Front Power Distribution Fuse Box located in the engine compartment, the Rear Power Distribution Fuse Box located in the trunk and the Passenger Junction Fuse Box located in the front right-hand foot well. All fuses and relays (except the trailer towing accessory kit) are located in the three fuse boxes.

Vehicle Networks
The Jaguar XJ employs three different networks: a CAN (Controller Area Network) for high-speed power train communications, an SCP (Standard Corporate Protocol) network for slower speed body systems communications, and a D2B (Optical) Network for very high-speed "real-time" audio data transfer. The D2B Network is a fiber optic network with a gateway to the remaining vehicle networks via the Audio Unit.Technician access to the three networks and the Serial Data Link is via the Data Link Connector.

Ground Studs
Circuit ground connections are made at body studs located throughout the vehicle. There are no separate power and logic grounding systems; however, there are a certain number of components that use unique ground points.