Brief Description
The Saab 9-3 is fitted with central locking system as standard on all markets. On certain markets the car is also fitted with TSL (Theft Security Lock) as standard.
On the US/CA market, the car is fitted with separate unlocking of the driver's door as standard. This means that the driver's door can be unlocked separately first and then the other doors when the key (passenger door also when using key) is turned once more, when the remote control button is pressed once more or the switch in the centre console pressed once more.
Each door is fitted with a lock assembly comprising a lock cylinder, microswitch and electric motor. The central locking system is controlled by the TWICE control module. Locking/unlocking can be done with a key, the remote control or the button in the centre console. The central locking system cannot be operated with the remote control when the key is in the ignition.
The central locking system can be operated with a key from the driver and passenger doors only. The lock has a freely rotating cylinder, which means the cylinder will just revolve if the incorrect key is used or there is an attempted break-in.
When the TSL (Theft Security Lock) is activated, all the car locks are blocked so that the doors cannot be unlocked by pulling up the lock button in the door. TSL cannot be activated while any of the doors is open.
If the central locking system is locked with TSL using the remote control or key (locked from outside), it will go to normal locked mode when the ignition key is turned to ON position and the correct immobilizer code has been identified. This is a safety function to prevent anyone driving off in a car with TSL activated.
The central locking system cannot be activated from inside with the lock button in the driver's door, only with the button in the centre console. Only the respective doors can be locked and unlocked with the lock buttons.
The car is delivered with two keys/remote controls but a further two can be programmed making a total of four keys/remote controls to each car.
P-bus and I-bus
A smaller number of control modules are connected to the bus in the Saab 9-3 compared with the Saab 9-5.
The two power train systems EDC and diesel pump are not connected to the I-bus, however. These systems require much faster communication to eliminate noticeable delays, e.g. when EDC requests a certain amount of fuel for injection.
Therefore, they are connected through a separate buss called the P-bus (Powertrain Bus). The P-bus has a data transfer rate ten times higher than that of the I-bus.
The P-bus is also connected to the MIU (Main Instrument Unit). The MIU ensures that the information that is available on one bus is also available on the other.