Antitheft and Alarm Systems: Service Precautions

IMMOBILIZER SYSTEM SERVICE CAUTION

CAUTION:
- When an immobilizer system component (such as the PCM, Immobilizer unit, coil or the key) has failed, It must be accurately determined according to the troubleshooting procedures or by the display of the DTCs prior to carrying out the service procedures.
- If a normal component Is mistakenly replaced and the ID number and/or code word are input into the new component, then neither component can be reused on other vehicles.
- When a new key registration or immobilizer unit and/or PCM replacement is performed on vehicles equipped with an immobilizer system, the new ID number should be registered using the procedure that includes engine cranking through idling. When the engine starts to reprogram the Immobilizer system, if the input voltage to the immobilizer unit becomes lower than the operation voltage of the Immobilizer system, the ID number can not be input momentarily. This is not a unit failure, so do not misunderstand during the problem diagnosis (when the terminal voltage goes back to the operation voltage, then the unit also begins to operate normally). Charge or replace the battery.