Immobilizer Systems: Programming: Introduction

If ignition key, immobilizer-ECU, or Engine Control Module/Powertrain Control Module (ECM/PCM) is replaced, or an ignition key is added, encrypted codes of all the ignition keys must be registered. A maximum of 8 ignition keys may be registered. See FUNCTION SELECTION  .

If ECM/PCM is replaced, immobilizer-ECU and ignition key should be replaced with it. Each ECM/PCM has an encrypted code for immobilizer-ECU. The ECM/PCM encrypted code is registered in immobilizer-ECU and ignition key using MUT-II Scan Tool (MB991502). If immobilizer-ECU has been replaced, scan tool must be used to input password. See FUNCTION SELECTION  . Obtain current password from vehicle owner.

Key ID registration (encrypted code) and password set are entered from special function menu. If key ID registration (encrypted code) and password set cannot be used, check for Diagnostic Trouble Codes (DTCs). After repairs, continue with special function menu selection(s).

If wrong password is entered 5 times in a row, immobilizer-ECU will determine an unauthorized operation is being attempted. Start-prevention mode will be set, engine operation will stop, and all special functions will be disabled. If ignition switch is turned to ON position and left on for about 20 minutes, start-prevention mode will be cancelled.