Abstract: A method is provided for formatting a message, with a first plurality of bits forming a data component, and a second plurality of bits forming a reserved component, for transmission in a vehicle. The method comprises the steps of calculating an initial checksum from the data component, calculating a revised checksum at least from the initial checksum, and storing the revised checksum in the reserved component. The number of bits in the reserved component is less than the number of bits in the data component.

Abstract: A method and apparatus is provided for validating a plurality of variable data transmitted in an automobile, comprising generating a control copy and a redundant copy of the variable data, calculating a pre-transmittal cross-check measure using the redundant copy of the variable data, and generating a transmittal message using the control copy of the data and the pre-transmittal cross-check measure.

Abstract: A vehicle control module for controlling an actuator unit in response to an input having a first processor, a first communication link coupled to the first processor, and a second processor coupled to the first processor via the first communication link. The first processor is configured to generate a first value based on the input, transmit the first value to the actuator unit, and receive a second value from the actuator unit based on a data received by the actuator unit from the first processor. The first communication link is configured to transfer the input and the second value to the second processor. The second processor is configured to determine a third value based on the input, and verify the first value based on a comparison of the second value with the third value.

Abstract: The invention concerns a network comprising an interconnecting network and several network nodes that are coupled to said interconnecting network and are designed to adapt their local communication time schedule to the communication time schedule of at least one other network mode, prior to being integrated as active network nodes. A network node to be integrated checks the activity of other network nodes and if no activity is identified, sends out positional messages for other network nodes, said message being fixed by predetermination in its communication time schedule. If a network node cannot be integrated as a reference node, it can only be integrated as an active node if it adapts its local communication time schedule to that of the reference node after receiving positional messages and if a check as to whether its own communication time schedule agrees with the communication time schedules of at least some of the active network nodes proves positive.

Abstract: Methods and apparatus are provided for insuring that a motor vehicle is being operated by an authorized operator. The apparatus includes an electronic control unit (ECU), an engine immobilizer unit, and a shared encryption key. The ECU generates a challenge by combining the output of a pseudo-random number generator and the output of a somewhat random number generator and cycling the combined number through a linear feedback shift register. The ECU sends the challenge to the immobilizer unit where it is encrypted with the shared key and sent back to the ECU as a response. The ECU uses the same key to encrypt the challenge and compares the encrypted challenge to the response. If the response matches the encrypted challenge, engine operation is enabled.

Abstract: Methods and apparatus are provided for determining the duration a motor vehicle engine may operate while operator authorization is verified in response to an ignition request. In one embodiment the method includes the steps of decrementing a pre-authorization timer from a first predetermined time limit and a maximum authorization timer from a second predetermined time limit in response to the ignition request. Also upon receipt of the ignition request an authorization process is initiated. Decrementing of the pre-authorization timer is halted in response to active operation of the starter motor of the motor vehicle, and operation of the motor vehicle is inhibited if either the pre-authorization timer or the maximum authorization timer decrements to zero before completion of the authorization operation.

Abstract: The invention refers to one of a number of nodes of a communication system. The nodes are connected to a communication media for transmitting data among the nodes. Said one node comprises a communication controller, across which the node is connected to the communication media, and a bus guardian for controlling access of the communication controller to the communication media. In order to provide a cheap but nevertheless reliable way for monitoring the synchronized clock signal of a node of a communication system and in particular for detecting deviations of the synchronized clock signal it is suggested that a synchronized clock signal from the communication controller is made available to the bus guardian, and that the bus guardian comprises means for monitoring the synchronized clock signal using a bus guardian internal clock signal, which is generated by means of an electronic circuit and which is less accurate than the synchronized clock signal to be monitored.

Abstract: Methods and apparatus are provided for sending an encrypted command message from a remote keyless entry device to a receiver in a motor vehicle. The method comprises defining a key generating key within the remote keyless entry device, and using that key generating key to generate a working key. The working key is transmitted from the remote keyless entry device to the receiver during a training session without transmitting the key generating key. The working key is modified each time the remote keyless entry device is placed in the training mode. After the training session, a message encrypted with the working key can be transmitted from the remote keyless entry device to the motor vehicle receiver where the encrypted message is decrypted with the working key.

Abstract: A method and a bit stream decoding unit for bit stream decoding has a bit stream comprising a number of consecutive samples. In order to provide for rapid and, in particular, reliable decoding of the bit stream, a detection window comprising a number of samples is defined and the detection window is positioned at certain positions on the bit stream in order to comprise certain samples with respective sample values. A majority voting is applied to the sample values in the detection window and, in dependence on the result of the majority voting, the bit stream is decoded and respective bit values are generated.

Abstract: The invention refers to a method for monitoring a communication media access schedule of a communication controller (5) of a communication system (1) by means of a bus guardian (6). The communication system (1) comprises a communication media (2) and nodes (3) connected to the communication media (2). Each node (3) comprises a communication controller (5) and a bus guardian (6) assigned to the communication controller (5). Messages are transmitted among the nodes (3) across the communication media (2) based on a cyclic time triggered communication media access scheme.

Abstract: Method for transmitting data within a communication system, the communication system comprising a communication media and a number of nodes connected to the communication media, the data being transmitted across the communication media within a communication cycle comprising a number of time slots assigned to one or more nodes of the communication system. In order to provide a possibility for a data transmission within communication cycles, which can satisfy the demands in communication systems for safety critical applications, too, it is suggested, that the communication cycle is initiated by an external event. The external event can be caused by manually setting a bit by a host, by a configurable timer in a controller host interface (CHI) or by an external trigger.