19/08/2026
🚘🔧 WHY DO SOME NEWER VEHICLES NEED A CAN FD ADAPTER WITH YOUR LAUNCH X431 SCANNER?
Have you ever connected your Launch X431 diagnostic scanner to a newer vehicle and discovered that it could not communicate with some control modules, even though the Bluetooth connector was properly connected?
The problem may not be your scanner.
The vehicle may be using CAN FD — Controller Area Network Flexible Data-rate.
🔍 WHAT IS CAN FD?
Older vehicles commonly communicate through Classical CAN, which can carry up to 8 bytes of data in one CAN frame.
CAN FD is a newer and faster development of CAN technology. It can carry up to 64 bytes of data per frame and can switch to a higher data rate during transmission.
Modern vehicles contain more electronic systems, sensors and control modules, so manufacturers need faster and more efficient communication between modules.
🔌 WHY IS THE CAN FD ADAPTER ATTACHED TO THE LAUNCH X431 VCI/BLUETOOTH CONNECTOR?
This is where many technicians misunderstand its function.
The CAN FD adapter does NOT increase Bluetooth strength or range.
Its job is to provide the required communication interface between the vehicle's CAN FD network and a compatible Launch X431 diagnostic VCI.
Think of the communication path like this:
🚗 Vehicle ECU/Modules
⬇️
🔌 OBD Diagnostic Port
⬇️
⚡ CAN FD Adapter
⬇️
📡 Launch X431 VCI/Bluetooth Connector
⬇️
📱 Launch X431 Diagnostic Tablet
The CAN FD adapter handles the vehicle-side CAN FD communication, while the Bluetooth connection transfers the diagnostic information between the VCI and the Launch tablet.
⚠️ WHAT CAN HAPPEN WITHOUT CAN FD SUPPORT?
On a CAN FD-equipped vehicle, a diagnostic interface that does not support the required protocol may experience:
❌ No communication with certain modules
❌ Incomplete system scanning
❌ Failure to identify some ECUs
❌ Difficulty reading or clearing fault codes
❌ Missing live data
❌ Failure to perform some special functions or diagnostic procedures
A technician may wrongly conclude that the ECU is faulty when the real problem is simply that the diagnostic interface cannot communicate using the vehicle's protocol.
🚘 WHICH VEHICLES USE CAN FD?
CAN FD is becoming increasingly important on late-model vehicles. Launch specifically identifies newer GM vehicles and CAN FD-equipped Jaguar and Land Rover vehicles among applications where CAN FD capability is important.
As automotive technology continues to advance, understanding communication protocols is becoming just as important as knowing how to use a scan tool.
💡 IMPORTANT FOR TECHNICIANS
Before diagnosing a newer vehicle, don't only ask:
“Does my scanner cover this vehicle?”
Also ask:
👉 “Does my VCI support the communication protocol used by this vehicle?”
Having the correct diagnostic software without the correct communication hardware can still prevent proper communication.
Also remember that some newer Launch X431 interfaces already have CAN FD capability built in, so an external CAN FD adapter is not required for every X431 model. Always confirm the capability of your particular VCI.
At CLIMAX SYSTEM SOLUTION LTD, we believe professional automotive diagnosis goes beyond reading fault codes.
It requires understanding how the vehicle communicates, how the modules interact, and which diagnostic equipment is required to communicate with them correctly.
🚗💻 Modern Vehicles Require Modern Diagnostic Knowledge.
