Immobilizer System

Schematische darstellungen

Schematic Diagram

Beschreibung und bedienung

Beschreibung

The immobilizer blocks the vehicle until the correct ignition key is used. In addition to the currently available anti-theft systems, such as alarm systems, the immobilizer helps to drastically reduce the theft rate.

1. 1

   Transponder (TP) — IMMO ECU Communication

   

   TP Communication Protocol

   1. After IGN ON (or CPU reset cancellation), the IMMO ECU sends a TP request signal, and the serial number and signature are received.

   2. If the response from the input transponder is not correct, the input is rejected.

   3. Wenn die Antwort des Eingabetransponders correkt ist, werden die Daten, die durch den Verschlüsselungsvorgang im EEPROM-Programm berechnet wurden, mit den vom TP empfangenen Daten verglichen.

      Wenn die Codes übereinstimen, ist die Eingabe abgeschlossen.

      Wenn die Codes nicht übereinstimmen, wird die Eingabe so lange fortgesetzt, bis die Codes übereinstimen.

   4. If the IMMO ECU EEPROM is not programmed but the corrected transponder is entered (CRC check OK), the input is accepted.

   5. After IGN1 ON (CPU reset cancellation), the IMMO ECU accepts a maximum of 5 transponder code attempts.

   6. If IGN1 is ON and EMS_state is locked upon receiving ACKNOWLEDGE, the TP is re-authenticated.

      

2. 2

   Transponder / IMMO ECU / EMS Authentication

   

COMPONENT FUNCTIONS

PCM (Antriebsstrang-Steuermodul)

1. The PCM (ECM) (A) verifies the ignition key using a special encryption algorithm programmed in the transponder and the PCM (ECM). Only if the result is identical can the engine be started. All vehicle-specific data of the transponder is stored in the PCM (ECM).

   The ERN (Encrypted Random Number) value between the EMS and the encrypted SMARTRA unit is checked, and the EMS decides on the validity of the coded key.

   

ENCRYPTED IMMOBILIZER UNIT (A)

Communication with the immobilizer is carried out via the transponder built into the key. Wireless communication uses RF (radio frequency of 125 kHz). The immobilizer is mounted behind the instrument panel near the cross member.

Das von der Antennenspule empfangene Funksignal wird von der Wegfahrsperren-Einheit in Meldungen für die serielle Kommunikation umgewandelt. Die vom PCM (ECM) empfangenen Meldungen werden in ein Funksignal umgewandelt, das über die Antenne zum Transponder übertragen wird.

The IMMOBILIZER does not perform a validity check and does not calculate the encryption algorithm. This device is only an interface that converts the received transponder signals into a series of data for the PCM (ECM) and vice versa.

TRANSPONDER (IN THE KEY)

The transponder has a special algorithm (calculation rule). During key learning, vehicle-specific data is stored in the transponder memory. This storage process can be performed only once. For this reason, the contents of the transponder memory can never be changed or modified afterwards.

[Hauptklappsschlüssel]

[Ersatz-Masterschlüssel]

ANTENNA COIL

The antenna coil (A) performs the following functions.

• Die Antennenspule versorgt den Transponder mit Energie.

• Die Antennenspule empfängt ein Signal vom Transponder.

• The antenna coil sends the transponder signal to the immobilizer.

  Sie befindet sich direkt vor dem Lenkradschloss.

Repair Procedures

KEY LEARNING PROCEDURE

1. 1

   SCHLÜSSELPROGRAMMIERUNG

   Das Verfahren zum Anlernen von Schlüsseln muss von der Werkstatt nach dem Ersetzen eines schadhaften PCM(ECM) oder zum Anlernen neuer bzw. zusätzlicher Schlüssel angewendet werden.

   The procedure begins with a PCM (ECM) request from the tester for the vehicle-specific data (6-digit PIN code) from the tester. The "unprogrammed" PCM (ECM) stores the vehicle-specific data, and key programming can begin. The "programmed" PCM (ECM) compares the vehicle-specific data sent by the tester with the stored data. If the data is correct, key programming can begin.

   If an incorrect user passcode or incorrect vehicle-specific data is transmitted to the PCM (ECM) 3 times, the PCM (ECM) locks the learning procedure for 1 hour. This time period cannot be shortened by disconnecting the battery or by any other manipulation. After reconnecting the battery, the timer starts the hour again.

   Key programming is performed with the ignition on using additional tester commands. PCM (ECM) parameters match the EEPROM data and the transponder data. The PCM (ECM) then verifies the storage process. If the result is positive, it sends a corresponding confirmation to the diagnostic tester.

   If the PCM (ECM) detects a key that was previously learned, the validity is accepted and the EEPROM memory data is updated. The transponder memory remains unchanged (this is not possible with a programmed transponder).

   Attempts to learn a key that has already been learned in the same learning cycle are detected by the PCM (ECM). The key is rejected and the ECM sends a corresponding message to the diagnostic tester.

   Attempts to learn invalid keys are also detected and rejected by the PCM (ECM). A corresponding message is sent to the diagnostic tester. The key may be invalid if the transponder is faulty or other reasons/data exist that make successful key learning impossible. If the PCM (ECM) detects differences between the authorization data in the PCM and in the transponder, the key is rejected.

   Es können maximal 4 Schlüssel angelernt werden.

   Tritt im Service-Menü der Wegfahrsperre ein Fehler auf, bleibt der PCM(ECM)-Status unverändert und ein spezifischer Fehlercode wird gespeichert.

   If the PCM (ECM) status and key status do not match during key learning, the check procedure stops and a specific fault code is stored in the PCM (ECM).

   

   1. PCM (ECM) Learning Status

      

      

   2. Not Yet Learned PCM (ECM) Status

      After replacing the PCM (ECM), the KDS indicates that the PCM (ECM) is in its original state in the key programming mode.

      The status "UNPROGRAMMED" means that no PIN code has yet been assigned to the PCM (ECM).

2. 2

   Verfahren zum Anlernen des 4-stelligen Benutzer-Passcodes

   The user passcode for limited override is programmed at the dealer service workshop. The vehicle owner can select a four-digit number.

   Programming of the user passcode is only possible for a "learned" PCM (ECM). Before the first learning of the user passcode, the PCM (ECM) status is "not programmed". The Limp Home function cannot be activated.

   The procedure begins by turning the ignition on with a valid transponder key (programmed key) and sending the user passcode via the diagnostic tool. After the user passcode is successfully learned for the first time, the status changes from "Unprogrammed" to "Learned".

   A learned passcode can also be changed. This is possible as long as the status is "Learned". To gain access authorization, send either the old passcode or the specific vehicle data to the ECM with the diagnostic tool. When access authorization has been recognized, transmit the new passcode to the PCM (ECM). The status then remains "Learned" and the new user passcode is valid.

   If an incorrect user passcode or incorrect vehicle-specific data is transmitted to the PCM (ECM) 3 times in succession or with brief interruptions, the PCM (ECM) blocks requests to change the passcode for 1 hour. This time period cannot be shortened by disconnecting the battery or by any other manipulation. After reconnecting the battery, the timer starts the one hour again.

   1. Learning a User Passcode

      

      

   2. Changing the User Passcode

      

      

Notlaufregelung

1. 1

   'LIMP HOME'-FUNKTION (NOTSTART) MIT DEM DIAGNOSEGERÄT

   If the PCM (ECM) detects a fault in the SMARTRA or transponder, the PCM (ECM) allows the immobilizer Limp Home function. The Limp Home function can only be activated if the user passcode (4-digit) has previously been issued to the PCM (ECM). This passcode is selected by the vehicle owner and programmed at the service station.

   Der Benutzer-Passcode kann über das spezielle Diagnosegerät-Menü zum PCM (ECM) übertragen werden.

   Only if the PCM (ECM) and user passcode status are "Learned" and the passcode is correct is the PCM (ECM) unlocked briefly (30 s). The engine can only be started during this time. After this time period has expired, the engine can no longer be started.

   If an incorrect user passcode is entered, the PCM (ECM) is blocked from requesting the Limp Home function for one hour. This time period cannot be shortened by disconnecting the battery or by any other manipulation. After reconnecting the battery, the timer counts one hour again.

   

   

2. 2

   LIMP HOME-FUNKTION MIT DEM ZÜNDSCHLÜSSEL

   Emergency start can also be activated with the ignition key. The user passcode can be entered into the PCM (ECM) by a specific ignition on/off sequence.

   Information about the PCM (ECM) and access code is required. User passcode status "Learned" and the passcode is correct, the PCM (ECM) is unlocked briefly (30 s).

   The engine can only be started during this time. After this time period has expired, the engine can no longer be started. After re-entering the passcode, the timer unlocks the PCM again for 30 seconds, during which the engine can be started.

   Nach Ausschalten der Zündung wird das PCM (ECM) 8 Sekunden nach Ablauf des Zeitgebers gesperrt. Für den nächsten Start muss der Benutzer-Passcode erneut eingegeben werden.

   

REMOVAL AND INSTALLATION

PROBLEM AND REMEDY:

AUTOMATIC CHECK OF ECM AND SMARTRA UNIT

Im Falle eines Defekts des ECM muss die Einheit durch ein "leres" oder "neutrales" ECM ersetzt werden. In das neue ECM müssen alle Schlüssel einprogrammiert werden. Schlüssel, die nicht in das ECM Programmiert werden, sind für das neue ECM ungültig (Siehe Verfahren zur Schlüsselprogrammierung). Die spezifischen Fahrzeugdaten müssen aufgrund der einzigartigen Transponderprogrammierung unverändert bleiben.

If the SMARTRA is defective, reprogramming must be performed. The old SMARTRA is simply replaced with the new one, which is then programmed.

1. 1

   Vor dem Ersetzen zu beachtenden Punkte (PCM (ECM))

   

2. 2

   Vor dem Ersetzen zu beachtenden Punkte (Schlüssel & zusätzliche Registrierung)

   

NEUTRALIZING THE ECM

Das PCM (ECM) kann über ein Diagnosegerät "neutralisiert" werden.

A learned ignition key is inserted and, after the ignition is turned on, the PCM (ECM) requests the vehicle-specific data from the diagnostic tool. The communication messages are described in the "Neutralization Mode". After successful data reception, the PCM (ECM) is neutralized.

Das ECM bleibt gesperrt. Die Limp Home-Funktion sowie die Für "Zweimaliges" Anlassen" werden vom PCM (ECM) nicht akzeptiert.

Learning the keys follows the procedure for an unprogrammed PCM (ECM). The vehicle-specific data must remain unchanged due to the unique programming of the transponders. If data must be changed, new keys with an unprogrammed transponder must be used.

With this function, the PCM (ECM) and keys are neutralized. For example, if a key is lost, the PCM (ECM) is neutralized and the data is transmitted to learn the key.

(See procedure for setting keys and PIN code of the PCM (ECM) in "Neutral Status" using a scan tool. If vehicle-specific data is transmitted incorrectly to the SMARTRA unit 3 times in succession or with brief interruptions, the SMARTRA unit blocks requests to activate neutral mode for one hour. This time period cannot be shortened by disconnecting the battery or by any other manipulation. After reconnecting the battery, the timer starts the one hour again.)

SMARTRA NEUTRALIZATION

Das ECM kann über ein Diagnosegerät "neutralisiert" werden.

The ignition key (regardless of key status) is inserted and the ignition is turned on. After receiving the correct vehicle password from the GST, the SMARTRA unit can be neutralized. Neutralization of the SMARTRA unit is possible if the DPN and the value entered by the GST match.

Neutral status. If the SMARTRA status is active, the EMS remains locked. The engine cannot be started even with "double ignition".

When the vehicle password is changed, a new sensor must be used. A new key can only be used after programming the vehicle password.

If incorrect vehicle-specific data is transmitted to the SMARTRA unit three times in a row or with brief interruptions, the SMARTRA unit blocks the request to activate neutral mode for one hour. This period cannot be shortened by disconnecting the battery or by any other manipulation. After the battery is reconnected, the timer restarts the one-hour period.