If you’re dealing with an invalid SOS error on a 2004 Mercedes E320, you can permanently disable the system using the MB STAR diagnostic software (DAS/Xentry). This issue often causes the sound to cut out randomly and displays a white TeleAid SOS warning error on the gauge cluster. Here’s a step-by-step guide to resolve the problem:
Solution:
The key to solving this issue is to deactivate the SOS system by changing the coding from EXISTENT to NOT EXISTENT using DAS/Xentry.
Requirements:
For vehicles older than 2006, you’ll need one of the following MB diagnostic systems:
Note: Neither an OBD2 scanner nor Xentry Passthru will work. A genuine MB Star multiplexer is required.
Step-by-Step Guide:
- Accessing the ECU Group:
- Go to ECU Group -> Information & Communication -> Audio, Video & Navigation -> ECU Adjustment.
- Select Read coding and change if necessary.
- Navigate to MOST specified configuration -> Telematics.
- Set the option to NOT AVAILABLE.
- Run coding to apply the changes.
- Adjusting the Control Unit Group:
- Go to Control Unit Group -> Main Unit -> CGW -> Control Unit Adaptation.
- Select Read coding and change if necessary.
- Navigate to Telecommunications -> Telematics.
- Set the option to NOT AVAILABLE.
- Run coding to finalize the changes.
- (Optional) Removing the Physical Control Unit:
- If desired, you can remove the physical SOS control unit from the vehicle.
- Ensure the fiber optic loop is reconnected to maintain system integrity. Replacement loops are available for around $10 on Amazon.
Important Note:
If the TELEAID system is left set to “PRESENT” in the airbag module, it may trigger SRS codes. The SRS system needs to communicate with the module while it is still installed in the car. Therefore, make sure to update the coding in the airbag module if you disable the SOS system.
By following these steps, you should be able to deactivate the SOS system and eliminate the annoying TeleAid warning and sound interruptions.