The new Jetta taxi with a mileage of about 89 thousand km in 2013. The car has automatic locking function, because it is not convenient for the taxi to switch the automatic locking function to the taxi. The taxi users require the service station to close this function. However, the function can not be closed to the use function of the vehicle connection diagnostic instrument or the fault guidance. Inspection and analysis: the connection diagnostics VAS6150 detects all control units without fault codes. Using the guide function to select the car model and enter the central door lock factory mode under the matching option function menu of the vehicle power grid control unit (BFM), the final result of the function failure is repeated repeatedly, and the automatic locking function can not be closed. A new Jetta vehicle with a non rental version is compared. It is found that the 09 part of the central electrical control unit is not in conformity with the standard vehicle. The medium version vehicle can adjust the functions directly through the guiding function, including the modification of the automatic locking function, and the lower version can not use the function to guide the lock function. Through research, we sum up the method of changing the part of the new Jetta taxis. Let's share it with you. The operation steps are shown in Figure 2. The conclusion is drawn from the function menu of the matching channel of the central electrical control unit BCM that changes in the coding of the control unit can also be changed while the function of the matching channel menu is changed, and the change of the vehicle function can be realized by changing the coding of the control unit. The automatic locking function of the door realization at a specific speed can be realized by changing the BCM code bytes of the central electrical control unit. The specific method is that the 0 byte "7C" is changed to "5C", and the middle matching code "7b" is changed to "6B", and the fault elimination: finding the matching channel for the change function and troubleshooting. If you do not understand the function of the vehicle, you should find a solution by comparing the proof.