Hyundai Sonata: Immobilizer System / Repair Procedures

Learning Procedures

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Key Learning Procedure Key learning must be performed after replacing a faulty Engine Control Module (ECM) or when providing additional keys to the vehicle owner. The procedure starts with the PCM (ECM) requesting vehicle-specific data (PIN code: 6 digits) from the tester. A "new" PCM (ECM) stores the vehicle-related data, and key learning can begin. A "learned" PCM (ECM) compares the vehicle-specific data from the tester with the stored data. If the data is correct, learning can continue. If incorrect data is sent to the PCM (ECM) three times, the PCM (ECM) will reject the key learning request for one hour. This time cannot be reduced by disconnecting the battery or any other action. After the battery is reconnected, the timer starts again for one hour. Key learning is performed with the ignition turned on using the key and additional tester commands. The PCM (ECM) stores the relevant data in the EEPROM and in the transponder. The PCM (ECM) then performs the authentication required to confirm the learning process. Successful programming is then confirmed by a message on the tester. If the key is already known to the PCM (ECM) from a previous learning, authentication is accepted and the EEPROM data is updated. The transponder content is not changed (this is not possible for a learned transponder). An attempt to re-learn a key that has already been learned during the same learning cycle is recognized by the PCM (ECM). The key is rejected, and a message is sent to the tester. The PCM (ECM) rejects invalid keys presented for learning, and a message is sent to the tester. A key may be invalid due to a transponder fault or other causes resulting from unsuccessful data programming. If the PCM (ECM) detects different transponder and PCM (ECM) authenticators, the key is considered invalid. The maximum number of learnable keys is 4. If an error occurs during the immobilizer service menu, the PCM (ECM) state remains unchanged and the specific fault code is stored. If the PCM (ECM) state and the key state do not match for key learning, the tester procedure will be stopped and the fault code will be stored in the PCM (ECM).

When learning the 1st key, the Smartra is registered at the same time.
1. PCM (ECM) Learning Status
2. PCM (ECM) Virgin Status: After replacing a new PCM (ECM), the GDS shows that the PCM (ECM) is in the virgin state in key learning mode. The "VIRGIN" status means that the PCM (ECM) has not previously matched any PIN code.
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User Password Learning Procedure The user password for Limp Home is learned at the service station. The vehicle owner can select a four-digit number. User password learning is accepted only by a "learned" PCM (ECM). Before the first entry of the user password into the PCM (ECM), the password status is "virgin" and the Limp Home function is not possible. Learning starts with the ignition turned on using a valid key (learned key) and the tester sending the user password. After successful learning, the user password status changes from "virgin" to "learned". A learned user password can also be changed. This can be done if the user password status is "learned" and the tester sends access authorization, either the old user password or the vehicle-specific data. After correct authorization, the PCM (ECM) requests a new user password. The status remains "learned" and the new user password will be valid for the next limp home mode. If incorrect user passwords or incorrect vehicle data are sent to the PCM (ECM) three times continuously or intermittently, the PCM (ECM) will reject the password change request for one hour. This time cannot be reduced by disconnecting the battery or other actions. After the battery is reconnected, the timer starts again for one hour.
1. User Password Learning
  
  If an incorrect password is entered, repeat the procedure from the first step after 10 seconds.
2. Changing the User Password

Limp Home Function

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Limp Home Mode from the Tester: If the PCM (ECM) detects a SMARTRA or transponder fault, the PCM (ECM) will allow the immobilizer limp home function to be performed. Limp home is possible only if the user password (4 digits) was previously transmitted to the PCM (ECM). This password can be selected by the vehicle owner and is programmed at a service station. The user password can be sent to the PCM (ECM) through the special menu of the tester. Only if the PCM (ECM) is in the "learning" state, the user password status is "learned", and the user password is correct, will the PCM (ECM) be unlocked for a limited time (30 sec.). The engine can only be started during this time. After the time has elapsed, engine starting is not possible. If an incorrect user password is sent, the PCM (ECM) will reject the limp home request for one hour. Disconnecting the battery or any other action cannot reduce this time. After the battery is reconnected to the PCM (ECM), the timer starts again for one hour.
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Limp Home mode can also be activated with the ignition key. The user password can be entered into the PCM (ECM) using a special ignition on/off sequence. Only if the PCM (ECM) is in the "learning" state, the user password status is "learned", and the user password is correct, will the PCM (ECM) be unlocked for a limited time (30 sec.). During this time, the engine can be started. After the time has expired, engine starting is not possible. After a new password has been entered, the timer (30 sec.) starts again. After the ignition is switched off, the PCM (ECM) is locked if the timer has passed 8 seconds. For the next start, the user password is requested again.

Replacement

Problems and Replacement Parts:

Symptom	Kit	GDS required?
All keys lost	Blank key (4)	YES
Antenna coil unit malfunction	Antenna coil unit	NO
ECM malfunction	PCM (ECM)	YES
Ignition switch malfunction	Ignition switch with antenna coil unit	YES
Unidentified vehicle-specific data appears	Key, PCM (ECM)	YES
SMARTRA unit malfunction	SMARTRA unit	YES

Replacing ECM and Smartra: If the ECM is faulty, the unit must be replaced with a "virgin" or "neutral" ECM. All keys must be learned to the new ECM. Keys that are not programmed to the ECM are invalid for the new ECM (refer to the Key Learning Procedure). Vehicle data must remain unchanged due to the unique transponder programming. If the SMARTRA is faulty, the SMARTRA must be learned. The new SMARTRA replaces the old one and the SMARTRA must be learned.

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Precautions Before Replacing the PCM (ECM)

Precautions before replacement (keys and additional registration)

When only one key is registered and you want to register another key, you must re-register the key that has already been registered.
When key No. 1 is registered and master key No. 2 is not registered, turn key No. 1 to the IG/ON or START position and remove it. The engine can be started with unregistered key No. 2. (Note: key No. 2 must be used within 10 seconds after removing key No. 1.)
When key No. 1 is registered and key No. 2 is not registered, turn unregistered master key No. 2 to the IG/ON or START position. The engine cannot be started even with registered key No. 1.
When inspecting the immobilizer system, refer to items 1, 2 and 3 above. Always keep the 10-second window in mind.
If the PIN code and password are entered incorrectly three times in succession, the system will be locked for one hour.
Be careful not to block the transponder areas.
Problems may occur when registering a key or starting the vehicle if the transponders are blocked.

Neutralizing the ECM: The PCM (ECM) can be set to the "neutral" state using the scan tool. A valid ignition key is inserted and the ignition is turned on. After the data is recorded, the PCM (ECM) requests vehicle data from the tester. Communication messages are described in "Neutral Mode". After successfully receiving the data, the PCM (ECM) is neutralized. The ECM remains locked. Neither the emergency mode nor the "double ignition on" function is accepted by the PCM (ECM). Key learning follows the procedure described for the primary PCM (ECM). Specific vehicle data must remain unchanged due to the unique transponder programming. If the data must be changed, new keys with a virgin transponder are requested. This function is intended to neutralize the PCM (ECM) and the key. Example: if a key is lost, neutralize the PCM (ECM), then learn the keys (refer to What to Do if a Key is Lost). The PIN code of the PCM (ECM) can be set to the "neutral" state by the scan tool. If incorrect vehicle-specific data is sent to the SMARTRA three times in succession or periodically, the SMARTRA will reject the request to enter neutral mode for one hour. Disconnecting the battery or other manipulations cannot reduce this time. After the battery is reconnected, the timer starts again for one hour.

Neutralization unit status

In case of PCM (ECM) status "Learned" regardless of user password "Virgin or Learned"
Enter the correct PIN code using the scan tool.
Neutralization meaning: Deletion of PIN code (6) and user password (4). : Locking of ECM (except key learning permission)

Neutralization value:

Deletion of PIN code (6) and user password (4)
Locking of ECM (except key learning permission)

SMARTRA Neutralization The EMS SMARTRA can be set to the neutral state by the tester. Insert the ignition key (regardless of key status) and turn to ON. After receiving the correct vehicle password from GST, the SMARTRA can be neutralized. SMARTRA neutralization is possible if the PIN is the same as the value entered by GST. If the SMARTRA status is neutral, the EMS retains the lock state, and engine start is not possible with the "double ignition" method. When the vehicle password is changed, only a new virgin transponder must be used. In the case of a virgin key, after learning the vehicle password key, it can be used. If incorrect vehicle data is sent to the SMARTRA 3 times continuously or intermittently, the SMARTRA will reject the request to enter neutral mode for one hour. Disconnecting the battery or other actions cannot reduce this time. After the battery is reconnected, the timer starts again for one hour.