IMMOBILIZER SYSTEM CONSTRUCTION/OPERATION

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• When a key is inserted into the key cylinder, the key ID number of the key and the key ID number registered in the PCM are compared. If the comparison is successful, permission is given to start the engine. For PCM control, see Section 01, CONTROL SYSTEM.
• Keys contain a unique ID number that is previously registered in the instrument cluster. Due to this, if immobilizer system component parts are replaced (such as key addition/clearing and instrument cluster replacement), it is necessary to reset the system.

Immobilizer System Release Operation

Immobilizer System Setting

• The immobilizer system can be set so that only the Mazda Modular Diagnostic System (M-MDS) must be used to perform system procedures. When using the Mazda Modular Diagnostic System (M-MDS), first security access must be requested. Obtain security access permission according the Mazda Modular Diagnostic System (M-MDS) screen and then perform system procedures.

Mazda Modular Diagnostic System (M-MDS) setting items

Contents

Programming an additional ignition key
Allows key ID number registration.
Ignition key ID number clearing
Clearing and registration of key ID numbers.
Parameter reset
Initialization of either of the following:
• PCM
• Instrument cluster
Customer spare key programming enable
"Method for adding other keys using two keys that can start the engine" is enabled.
Note
• This is the default setting on new vehicles.
Customer spare key programming disable
"Method for adding other keys using two keys that can start the engine" is disabled.
Note
• When only the Mazda Modular Diagnostic System (M-MDS) must be used to register key ID numbers, making a forged key by using two keys that can start the engine is prevented. This function is for use by rental car or other companies with vehicle fleets.

• When immobilizer system component parts (key, Instrument cluster, PCM, and coil antenna) are replaced, the system must be reset as described below. For setting method details, see Mazda3 Workshop Manual.

Component part

Setting

Key addition
Key ID number of added key must be registered. Key ID number registration is performed according to the following methods:
• Method for registering other keys using two keys that can start the engine
• Method using the Mazda Modular Diagnostic System (M-MDS)
Key clearing
The registered key ID number can only be cleared using the Mazda Modular Diagnostic System (M-MDS). When clearing a key ID number using the Mazda Modular Diagnostic System (M-MDS), all key ID numbers are cleared.
PCM replacement
Parameter reset must be performed.
Instrument cluster replacement
• Parameter reset must be performed.
• The key ID numbers for all keys that were being used must be registered in the Mazda Modular Diagnostic System (M-MDS). Two or more keys must be registered.
Coil antenna replacement
Resetting of the immobilizer system does not need to be performed.