On Board Diagnostic, technical data: Equipment

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2003 Audi S8, 2003 Audi A8, 2002 Audi S8, 2002 Audi A8, and 2001 Audi A8. However, it is still accessible from the selected car via links, so may be relevant.

The term "OBD" relates specifically to the electrical and electronic part of the control system.

The control module is equipped with a Diagnostic Trouble Code (DTC) memory so that the malfunction can be traced quickly in the event of an electronic/electrical component failure or an open circuit.

The advantages of OBD can only be fully exploited by using the vehicle diagnostic, testing and information system VAS 5051 or the VAG 1551 scan tool, in operating mode 1 "Rapid data transfer."

Functions which can be identified by the vehicle diagnostic, testing and information system VAS 5051 and the VAG 1551 scan tool can be identified in AVAILABLE FUNCTIONS , list of available functions.

The DTC memory is equipped with a permanent memory and therefore does not depend on the power supply.

NOTE:

Every time the DTC memory is erased the readiness code must be generated. See READINESS CODE, GENERATING .
The Exhaust Malfunction Indicator Light (MIL) in the instrument cluster will be switched on if the engine control module recognizes malfunctions which have an affect on exhaust emissions. See EXHAUST MALFUNCTION INDICATOR LIGHT (MIL), SIGNIFICANCE .
Malfunctions relating to the electronic throttle are also indicated by a Electronic Power Control (EPC) warning light in the instrument cluster. See ELECTRONIC ENGINE POWER CONTROL (EPC) WARNING LIGHT IN INSTRUMENT CLUSTER, SIGNIFICANCE .