Immobilization System: Notes

The ECM and the body control unit (BCU) security system comprise the immobilization system.

The ECM and the BCU combine to prevent the engine from running unless the appropriate security criteria are met.

The ECM and the BCU are a matched pair, if either one is replaced for any reason, the system will not operate unless the replaced unit is correctly matched to its original specification. Textbook/T4 must be used to reconfigure the immobilization system.