Keyless Entry: Service and Repair
HOW TO REGISTER SECRET CODERequired Special Tools:
- MB991958: MUT-III Sub Assembly
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991910: MUT-III Main harness A
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.
WHEN SPECIAL TOOL MB991824 (V.C.I.) IS USED
1. Check that the doors lock normally when the key is used.
2. Insert the ignition key.
CAUTION: To prevent damage to special tool MB991824 (V.C.I.), always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting special tool MB991824 (V.C.I.).
3. Connect special tool MB991824 (V.C.I.) to the data link connector.
4. Press the hazard warning light switch six times within 10 seconds.
NOTE: When the hazard warning light switch has been pressed six times, the ETACS-ECU locks and unlocks the doors automatically once. The ETACS-ECU is ready to register an encrypted code.
NOTE: The hazard warning light switch is a toggle switch.
5. Press the transmitter button, and then press it two times within 10 seconds of the first press. This will register the code.
6. When the encrypted code has been registered, the ETACS-ECU locks and unlocks the doors automatically once.
7. If you are using two or more transmitters or have added a second transmitter, the next transmitter should be registered within one minute after registering the code for the previous transmitter. The registration procedure is common for all the transmitter.
8. Registration mode will be canceled under the following conditions:
- When the secret code for four transmitters has been registered;
- When passing one minute after finishing the registration of all transmitters;
- When special tool MB991824 (V.C.I.) is disconnected;
- When the key is removed from the key cylinder;
9. After the registration is completed, remove the ignition key and close all the doors, and then check that the keyless entry system operates normally.