Saab 9-3: Electrical Architecture

High-Speed Connections

• Most extensive systems use of fiber optic technology
• Platform for advanced infotainment systems
• OnStar telematics standard

“The advanced electronic systems in this car give us a powerful platform to accommodate all likely developments in the fast-moving fields of infotainment and e-services.”
– Patrick Lundblad, Infotainment and e-services specialist, new Saab 9-3

All major mechanical and electrical functions in the new 9-3, including numerous driver and passenger comfort features, are precisely and reliably controlled through an advanced digital signal network.

It incorporates the auto industry’s most extensive systems application of fiber optic technology. This provides a signal capacity 50 times greater than the fastest conventional wire links and offers a secure platform for the application of advances in telematics and communications, enabling new 9-3 owners to conveniently install new functions as technology evolves.

The entire electronic and electrical network uses databus transmission – often referred to a “multiplexing” – to connect groups of electrical subsystems and pass on signals from all the car’s sensors. In this way, a CANBUS (Controller Area Network) uses just one or two wires with microprocessors, transistors and LEDs (Light Emitting Diodes) to replace a complicated wiring harness and all its associated relays, switches and bulbs.

CANBUS technology offers great benefits in weight saving, reliability and data transmission capacity. It is used to connect the new 9-3’s main subsystems: powertrain, chassis, body, “infotainment,” OnStar telematics, and climate and comfort systems.

Smart networking
A battery of sensors are the “nerve endings” of the new 9-3 and the data they provide is dispatched as packages of digital signals, or buses, along three information “highways,” stopping where required at 44 sub-stations, or microprocessors, for analysis and subsequent action. A powerful control module governs each of these highways and their substations; all three integrated with each other to ensure there are no “traffic jams” or conflicting requirements.

If all the functionality of the new 9-3 was to be achieved using a traditional, complex wiring harness, it would weigh twice as much, at least 90 pounds, and be twice as long, at more than 5,000 ft.

A single wire highway, or “low speed” Bus, with a capacity of 33 kbits per second, connects functions within the car: the ignition switch, steering column lock, airbags, the main instrument panel, interior lighting, doors, mirrors, windows, security alarm, gear-shift position and, when equipped, the sunroof, electrically-operated seats and parking assistance.

Powertrain control, the Trionic 8 engine management system, ABS, TCS, ESP and related functions are all connected by a dual wire, ”high speed” Bus, with a transmission capacity 15 times greater at 500 kbits per second.

Fiber optic innovation
The third highway is the largest yet fitted to a passenger car, using fiber optics instead of wire to give a massive capacity of 25 Mbits per second, 50 times greater than that of a dual wire bus. It is utilized by the audio systems, including the available in-dash 6-disc CD changer, and OnStar telematics.

The fast-moving world of information technology is likely to place increasing demands on the in-car time of drivers and passengers, and the new Saab 9-3 is configured to accommodate all likely future developments in digital communication to and from the car.

OnStar telematics
General Motors’ OnStar telematics service is standard on the Saab 9-3 in the United States and will be available for the European market when the infrastructure is in place.

Utilizing an AMPS phone and GPS tracking, OnStar provides a range of services including 24-hour access to an emergency support center, an automatic alert following airbag deployment and stolen vehicle tracking. Dozens of additional convenience services are also available, such as route guidance, roadside assistance and carrying out numerous information, booking and reservation requests. The OnStar support center can even assist in locating the car in a crowded parking lot by activating its lights and horn. Twelve months of OnStar Safe and Sound program service is included at no charge.

OnStar also offers Personal Calling, a wireless, hands-free phone service, available for an additional usage fee. An additional feature, Virtual Advisor, allows the user to configure and customize Internet-based information services to allow the driver to hear news, weather, sports, or even e-mail using simple voice commands in the car.

New Saab 9-3 In Focus: The Electronic Key?
The Electronic “key” to the new 9-3 is, of course, simply a means of operating a transponder. But what shape should it be? A car ignition key may now look like a credit card or a rubber ball, either using a unique PIN code to initiate a signal or sending a signal through a transponder.
Saab found the answer in a long-held Scandinavian design principle which states that “form should always follow function!”

Using a “credit card” activation key also means pressing a “start” button. It may be fun, but it is not good ergonomics. Two separate movements are not necessary when one traditional “engage” twist, is all that’s needed.

“The design department was involved from the start in deciding the shape of the Electronic key, “ says Saab product marketing specialist Fritz Magnusson . “We have something different which is quite hi-tech but still very ergonomic and easy to use. It is an item the owner can identify with and represents the sophisticated character of the new car. If the car ever has a flat battery, you can simply pull out the metal blade and still get into your car.”