The working mode of the original car burglar alarm is: press the lock button with the original car remote controller, and the original car receives the wireless radio frequency signal sent by the remote controller and matches it with the radio frequency code stored in ECU. Once the received RF code is identified, ECU will send an unlocking signal to the central door lock actuator to execute the unlocking action; Otherwise, the unlocking operation will not be performed. This paragraph mainly describes the on/off lock mode of the remote controller, which mainly uses the stored radio frequency code and related information to carry out matching authentication and realize the on/off lock action.
This method requires ECU to judge before the above operation! If you use the key to open/close the lock, there will be no RF signal transmitted to the ECU for judgment, and the on-board computer will think that the external operation is illegal and trigger the audible and visual alarm prompt of the original car! ! Remarks: Opening/closing locks with keys is mainly an emergency method provided by manufacturers to users. The remote control of the original car will only be used if there is no battery. Once the acousto-optic alarm of the original car is started, there are two solutions: the first one is to open/close the lock once with the remote control of the original car by wireless, and the second one is to open the engine compartment, disconnect the negative battery for 3-5S, and reinstall or remove it!
Source of Information: Concept 90 Automobile Service