Good day. Thank you for your question.
FMB140 has a CAN data processor inbuilt that allows it to extract CAN data from vehicles. There are 2 modes in FMB140 ( LVCAN200 mode or ALLCAN300 mode) which have their own range of parameters that can be read, of course, ALLCAN300 being the advanced mode since it has an Advanced software version. You may choose your FMB140 mode based on the vehicles that you want the CAN data from. Another factor is that each manufacturer has its own range of parameters that can be read depending on the vehicle model, year of manufacturer, and equipment.
You may refer to our Wiki page for the supported vehicles list, as follows
For LVCAN200, refer here - https://wiki.teltonika-gps.com/view/LV-CAN200#Supported_vehicles_list
For ALLCAN300, refer here - https://wiki.teltonika-gps.com/view/ALL-CAN300#Supported_vehicles_list
If your vehicle model is on the list then you may check with us via VIP Helpdesk for the scheme provision on the CAN wire connection because we do not share any schemes or other files on the community forum. If you do not have an account on VIP Helpdesk, kindly contact your Distributor/Sales Manager or reach them at our official website https://teltonika-gps.com/ and click on the "Contact Us" button. When you click, please fill the form and submit it. Note: as a topic, please choose "Vehicle telematics" or you can send an e-mail with the description of your situation to firstname.lastname@example.org
However, if your vehicle is not on the supported list then you may use the OBD port in the vehicle by auto-scanning to check if the fuel consumption data is available for that particular vehicle. For further details on this, kindly refer here https://wiki.teltonika-gps.com/view/FMB140_autoscan_feature_instructions
Please take note that you will need to update the device Firmware (request via VIP Helpdesk) to the latest version and the CAN firmware version via FOTA WEB (request via VIP Helpdesk) to ensure that more parameters can be obtained from the vehicle.
For the steps to update via FOTA WEB, please refer here - https://wiki.teltonika-gps.com/view/FMB140_CAN_connection,_SIMPLE-CAN_/_MINI-CAN_connection#FMB140_CAN_software_update_Over_The_Air
Please go through this and let me know if it helps.