Immobilizer System: Notes

The immobilizer system consists of the ignition key, the key ring antenna, the immobilizer-ECU, and the engine control module (ECM). The ignition key has a built-in transponder. Only the registered ignition key permits the engine to start, therefore, the engine can never be started by means of a forged key or by connecting the ignition wiring directly. The system is significantly safe and reliable against theft. In addition, the driver has only to turn the ignition switch to the "ON" position to activate the immobilizer system. If the requirements for starting the engine are not satisfied, the engine will be immobilized. If a registered ignition key is lost, all your ignition keys need to be registered again using scan tool MB991958 (M.U.T.-III Sub Assembly) to ensure security (Refer to ON-VEHICLE SERVICE  ). An additional ignition key can be registered as follows (only if two registered ignition keys are available):

• Using scan tool MB991958 (M.U.T.-III Sub Assembly) (Refer to ON-VEHICLE SERVICE  ).
• By operating two ignition keys that have been already registered (Refer to ON-VEHICLE SERVICE  ).