1. Presentation
#About this guide
This guide explains how VisionFT line VCUs communicate over a CAN network and how to configure that communication in the FuelTech Vision software. VCU (Vehicle Control Unit) is the FuelTech control unit installed in the car: the FT700 and the FT470. The guide starts with the basics (what a CAN network is, how a frame is built, what changes in CAN FD) and moves on to the everyday tools: the VCU's CAN ports, FuelTech devices, Customizable CAN, DBC file import and the sniffer.
If you already know CAN, go straight to the configuration chapters (6 onward). If you are just starting, read chapters 2 to 5 first: almost every communication problem comes from a detail of the theory (termination, bit rate, byte order, signal scale). If you are only connecting FuelTech products, chapters 7 and 8 have what you need. If you are not the person who configures the network (the car's driver, for example), read at least the warning and the "Before connecting to the vehicle" list at the end of this chapter: the list is carried out by whoever installs or configures the network (the tuner or the installer), and for the driver it shows what to ask them for and what to check with them. The technical terms in the list are explained in the Glossary at the end of the guide.
#Where to start
| I want to... | Chapters |
|---|---|
| Connect a FuelTech product (O2 sensor, injector driver, ignition, expander) | 7 CAN ports and 8 FuelTech devices |
| Send data to a third-party dash or datalogger, or read a third-party sensor or module | 10 Customizable CAN and 13 Examples |
| Connect a third-party inverter, BMS (battery management system) or charger in an electric vehicle | Outside the scope of this guide. Before any configuration, read the warning in this chapter. |
| Use the DBC file that came with the equipment | 11 Import and export DBC |
| Feed a dash that already reads the FuelTech format | 9 CAN custom packages |
| Find out what a module is transmitting | 12 CAN Sniffer |
| Troubleshoot a communication problem | 14 Troubleshooting |
#Who this guide is for
- Tuners and installers who need to connect the VCU to a dash, transmission module, injection module, sensor or the vehicle's original (OEM) network.
- Anyone who wants to read data from a third-party module or send data from the VCU to it.
- Teams that receive a DBC file from an equipment manufacturer and need to use it in the VCU.
#Versions covered
This guide describes the FuelTech Vision 3.0 software and the VCU 3.0 firmware (version 00.03.00.01), on the FT700 and FT470 VCUs. In earlier versions some fields may have a different name or may not exist. Always update the software and firmware before configuring the network.
#Before connecting to the vehicle
- Save a copy of the map.
- In VCU settings > CAN ports, check each port in use: turned on, Operation mode (FTCAN 2.0 for FuelTech products, RAW mode for the vehicle and third-party equipment), Baudrate (the bit rate) equal to the network's (in RAW mode the default is 1000 kbps) and CAN Terminator (the VCU's 120 Ω resistor for the end of the bus; on by default; leave it on only if the VCU is at one end of the bus). This also applies if you only listen to the network: a port at a different rate generates errors that disturb the other modules.
- Write the map (Write VCU button) and turn the VCU off and back on (power-cycle it): port changes only take effect at power-up (chapter 7).
- In Customizable CAN (the tool for frames you define yourself), a scale below 1 or a negative offset requires Arithmetic channel on, the signal field that makes the VCU calculate with real numbers (chapter 10).
- After importing a DBC (the file that describes the equipment's messages), disable the frames you will not use before writing: otherwise they transmit zeros on Port A (chapter 11).
- On the bench, connect at least one other module to the port: alone on the bus the VCU cannot transmit, because no module acknowledges its frames (chapter 10).
- Before trusting a signal, check a known value in real time (chapter 3).