Programming spare keys for VAG vehicles with MQB49 (5C/5D) immobilizer systems—such as the 2023 Volkswagen T-Roc—can be completed on bench using Launch X431 X-Prog5 and X431 series diagnostic tablets.
Required Tools
•Launch X431 Tablet (IMMO Plus, PAD V Elite, or PAD VII Elite) with activated VAG IMMO software
•X431 X-Prog5 (PROG5/G5) IMMO programmer
•MCU V1 Cable
•Soldering station & power cable
•Blank MQB49 5C/5D key
Step 1: System Connection
1.Connect Launch G5 programmer directly to X431 tablet using the built-in USB interface.
2.Supply external power to G5 module.
Step 2: System Pathing & Diagram Verification
1.Power on the tablet and open: Immobilizer -> System Mode -> Immobilizer Key Programming -> Key Learning -> MQB Immobilizer System.
2.Select MQB49 5C/5D from the menu list.
3.Open the pinout menu to identify the exact MCU V1 connection points for your PCB revision.
Step 3: MCU V1 Soldering (Working Key)
1.Disassemble the original working key shell and retrieve the PCB.
2.Solder the MCU V1 leads to the matching test points on the circuit board.
3.Plug the DB25 end of the MCU V1 cable into Launch G5 primary port.
Step 4: Data Reading, Dealer Key Generation & Adaptation
1.Run the MCU data read function. X-Prog5 reads the board, extracts the component security (CS) code, and generates an IMMO bin file.
2.Save the IMMO data file locally on the tablet.
3.Desolder the MCU V1 cable from the original PCB.
4.Solder the MCU V1 cable to the target blank key PCB using the same wiring layout.
5.Connect the blank key to X431 X-Prog5 programmer via the MCU cable.
6.Select Generate Dealer Key.
7.Once the dealer key is successfully generated, run Key Learning and follow the onscreen prompts to write the key into the immobilizer system.