Diagnostic Strategies: Overview

Overview

Data is provided to the instrument cluster from other subsystem modules in the form of controller area network (CAN) messages. The instrument cluster identifies the signals and displays the appropriate message in the message center. Most messages are accompanied by a chime or series of chimes which are requested by the module generating the message. The driver can view system status messages which are current within the instrument cluster software by pressing and holding the trip reset button for more than 3 seconds, the information display will then display the current messages in priority order. For more information, Communications Network and Instrument Cluster

Car configuration file (CCF)

CAUTION: If a new instrument cluster is to be installed, the instrument cluster renewal procedure must be carried out using the approved diagnostic system. This will ensure that the CCF data is correctly transferred from the central junction box (CJB) to the replacement cluster. The CCF will also need to be updated using the approved diagnostic system if the vehicle is modified in service from its original factory specification. This can include the fitting of non-standard wheels and/or tires and optional accessory dealer fit components with an electrical interface, such as park distance control.

The CCF contains all relevant data about the specification and market condition of the applicable vehicle, immobilization codes and driver personal settings. This information is retained in the CJB, the engine control module (ECM) and the instrument cluster enabling each system module to detect which systems and components are fitted to the vehicle. The information is continuously transferred between these three system modules to ensure that the data is constantly backed-up between the modules.