Secret Code Registration Method

Each individual secret code is registered inside the transmitter, and so it is necessary to resister these codes with the EEPROM inside the receiver in the following cases.

• When the transmitter or ETACS-ECU is replaced
• If more transmitters are to be used
• If it appears that a problem is occurring because of faulty registration of a code.

A maximum of four different codes can be stored in the EEPROM memory (four different transmitters can be used). When the code for the first transmitter is registered, the previously registered codes for all transmitters are cleared.

Therefore, if you are using four transmitters or are adding more transmitters, the codes for all transmitters must be registered at the same time.

1. Check that the doors lock normally when the key is used.
2. Insert the ignition key.
   CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
   Fig 1: Connecting Scan Tool To Data Link Connector

   Courtesy of DAIMLERCHRYSLER CORPORATION
3. Connect the scan tool to the data link connector. If the scan tool is not used, ground terminal (1) of the data link connector.
   NOTE: This will connect terminal (1) of the data link connector to ground, and the system will be in secret code registration standby mode.
   Fig 2: Locating Data Link Connector Terminals

   Courtesy of DAIMLERCHRYSLER CORPORATION
4. Press the hazard switch six times within 10 seconds.
   NOTE: If the switch is depressed six times, all the doors will be locked and then unlocked to enter the registration mode.
   NOTE: The hazard warning light switch is turned on and off alternately whenever it is pushed.
5. Press the transmitter switch, and then press it two times within 10 seconds of the first press. This will register the code.
6. Once the registration has completed, all the doors will be locked and then unlocked.
7. If you are using two or more transmitters or have added a second transmitter, the same registration procedure should be carried out within one minute after registering the code for the first transmitter.
   Fig 3: Blinking Timing Pattern - Hazard Switch

   Courtesy of DAIMLERCHRYSLER CORPORATION
8. Registration mode will be canceled under the following conditions:
   • When the secret code for four transmitters has been registered;
   • When one minute has been passed after registration mode started;
   • When scan tool MB991502 is disconnected (the ground connection is broken);
   • When the key is removed from the key cylinder;
9. After the registration is completed, carry out the following work, and then check that the keyless entry system operates normally.
   • Remove the ignition key.
   • Close all of the doors.