A new feature has been introduced to Xhorse VVDI Key Tool Plus for adding spare keys in the MQB 5C immobilizer system. This guide walks through the process while highlighting critical pitfalls to avoid, as a simple mistake can permanently disable a vehicle’s only key.
Step-by-Step Process
Accessing the Function: Start by selecting the vehicle brand (e.g., Volkswagen), then navigate to Immobilizer > MQB system. Choose the MQB49 5C specific system, in this case, Instrument MQB 495C (5C), and confirm the selection.
Reading the Key: Two main options appear for reading the key data: one for standard keys and another for “smart” keys. The correct choice depends on your key type. The crucial step is selecting the “Disassemble key and read data” option.
Critical Hardware Warning: The procedure requires connecting cables to the key’s circuit board. A major warning is issued here: the cable colors are misleading.
Two cable versions exist: MCU V1.0 and MCU V1.1.
On the V1.1 cable, a wire marked “RED” on its insulation is physically purple. Connecting this purple wire to the key’s board because it’s labeled “red” will destroy the key.
Always follow the written label on the connector (e.g., “MCU V1.1”) and the on-screen pinout diagram, not the physical wire color.
Soldering the Connection: The CLK (clock) cables are very short and must not be extended. They must be carefully soldered to specific processor pins (e.g., pin 24), as shown in the software’s diagram. Precision is essential to avoid short circuits.
Key Identification: Before proceeding, check the key’s internal model number (e.g., 5D for newer models post-2023). Using the wrong procedure for an unsupported key type can immobilize the vehicle.
Reading Data: Once correctly connected, initiate the read process. A successful read provides the data needed to generate a new key.
Additional Options: The software offers functions for keys with variable IDs, allowing you to rename them or create “clone” chips (which may only start the car without remote functions).
Important Notes for MQB 5D Keys
The process for newer 5D system keys (common from 2023) is similar but uses a different key design. The same critical cable warning applies: use the correct purple wire from the V1.1 cable set, not the one misleadingly labeled “red.”
Troubleshooting and Software Setup
If the MQB49 5C/5D functions don’t appear in your diagnostic tablet:
Ensure you have the latest database update (e.g., version 100 or newer).
The software mode must be version 140, 142, or 143.
The programmer (prog) version should be 187 or 188.
If options are missing after an update, try re-downloading and reinstalling the update package, as batch updates can sometimes fail.
General Advice and Conclusion
This tool is powerful but must be used with extreme caution and attention to detail. Always double-check connections against the diagrams, not the wire colors.