On-Board Diagnostics (OBD)

WARNING: This page is about a different car, the 2001 Jaguar XKR and 2001 Jaguar XK8. However, it is still accessible from the selected car via links, so may be relevant.

Vehicles use programmed electronic control systems to provide engine management and emission regulation, automatic transmission operation and anti-lock braking control. These control systems have an integral On-Board Diagnostics (OBD) facility for use in conjunction with either Jaguar diagnostic equipment or a scan tool which is capable of retrieving DTCs, PIDs and performing active commands.

The OBD information in this service information provides diagnostic and rectification procedures for emission related electrical and mechanical systems. The information is intended to facilitate fault diagnosis and the subsequent rectification of vehicles without recourse to the portable diagnostic unit (PDU).

OBD related information can be found in the following:

General Information
Engine Management System
Automatic Transmission
Anti-lock Braking System

Where appropriate an article comprises the following sub-sections:

Description and Operation

A general illustration and parts list to help the identification of the particular system or component.
A brief description of the system operating characteristics and monitoring procedure accompanied by a component illustration.
Additional information, where appropriate, is provided in the form of component calibrations, characteristics and cross sectional views.
A localized circuit diagram is included to provide circuit identification and details of connectors, splices, fuses, wire gauge and colors. See CIRCUIT DIAGRAMS .

Diagnosis and Testing (dedicated to fault analysis and rectification)

Recommended special tools.
Symptom chart; a chart containing all relevant Diagnostic Trouble Codes (DTC), their possible causes and an indication of the appropriate test.
Specific pinpoint test(s), designed so that fault diagnosis can be carried out in a logical and efficient manner.

NOTE: For convenience, pinpoint test illustrations indicating voltage measurements do not always accurately reflect the conventional method of connecting a multimeter. More explicitly, if the multimeter probes are connected as shown in some illustrations (positive probe to ground), the voltage reading would be preceded by the negative sign '-', indicating that the probes have been connected in the reverse manner to the normal convention. The accuracy of the reading is not affected and the '-' sign can be ignored when comparing the reading with the results indicated in the text of the pinpoint test.

Removal and Installation

Removal procedure(s), formatted in the recommended sequence
Illustrated guide to the use of special tools
Illustrations to support the relevant text
Installation procedure as above and including special recommendations for processes, lubricants and tightening torques.