5 COMPONENTS Description of components XF 95 series 2.2 VEHICLE SPEED SENSOR The vehicle speed sensor has two connections for output signals. The real-time speed signal, triggered by a Hall IC, is sent via the first connection, Via the other connection, a data signal (bi-directional signal) is sent, which involves an exchange of data between the MTCO and the speed sensor. The MTCO requests data from the sensor. The sensor sends the coded data to the MTCO in sequence, and the MTCO checks the accuracy of this data. The coded signal consists of the following data: 2 - Serial number of the sensor - Master key (the same as that of the MTCO) - Coded speed signal 4. 3. 2. 1.
- + In the MTCO, the coded speed signal is compared with the real-time speed signal. The MTCO sends commands and data to the sensor at 10-second intervals. Speed data for the CAN system is sent via MTCO outputs A4 and A8. Speed data for the UPEC system and ECAS system are sent for UPEC via output B7 and for ECAS and EMAS via output B6; these are duty cycle signals. 1 E501055 Duty cycle speed signal The speed signal sent via the vehicle speed sensor to the MTCO is processed by the MTCO and sent as a message via the CAN network. The speed signal is also converted into a duty cycle signal.
This signal is used by electronic units that do not receive/read the vehicle speed signal message via the CAN network. The diagram alongside shows the linear characteristic of the duty cycle (%) in relation to the vehicle speed (V). This graph applies to all vehicle models. % 44 22 50 100 V(km/h) E501057 2-2 200303 - +