History

History







In earlier cars each control module handled a specific function. Cars with a trip computer required an extra control module to run the trip computer functions. If a problem arose in a control module it was replaced, regardless of whether the fault was a hardware or a software fault.

As the number of variants and functions in the car has increased, it became ungainly and uneconomical to have a control module for each function. This required a new type of electrical system. This new electrical system uses distributed functionality, Controller area network (CAN) communication and re-programmable control modules.

Distributed functionality means that a function does not need to be connected to a single control module. A single function can be divided between several different control modules.

An example of this is the lock and alarm on the S80. The lock and alarm system function is distributed between the central electronic module, the upper central electronic module, the driver's information module, driver's door module, passenger door module and the rear electronic module.

The Controller area network (CAN) is a digital high speed network, which allows the control modules in the car to send a large amount of information in an extremely short time.

Re-programmable control modules allow increased functionality programming, without needing to replace the control module. This reduces customer repair costs.

Software downloading has a number of advantages:
- To obtain a new function, for example to add a trip computer to a car without a trip computer a new lever is installed and a new Car configuration file is downloaded into the central electronic module. The control modules in the remainder of the car use the Car configuration file to function in a particular way. The software in the driver information module, for example, reads off whether the trip computer information is to be displayed or not depending on the car's level of equipment.
- Fewer control module variants. A good example is the engine control module (ECM). There are 60 different engine variants, which previously required 60 different replacement parts needing to be held in stock. Using software downloads three different hardware types can manage all the variants.
- Adapting for the market. The application file for the driver information module can be the same for all markets. However, different market files can be downloaded to distinguish different market requirements.
- Language. The language in the combined instrument panel can be changed by downloading different language files to the driver information module.
- Makes faster introduction of improved functionality possible.
- Time saving when working with a particular type of fault. Previously it was necessary to replace a control module where a software upgrade can now be downloaded instead.