Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Security On Most
Model year 2007 and 2008
Model year 2009-2010
Model year 2011
The function Security on MOST prevents unapproved control modules in the infotainment system from being installed in the vehicle. This is to prevent the theft of units.
The function is controlled by the infotainment control module (ICM). The infotainment control module (ICM) checks the serial numbers of all the control modules in the MOST network and compares these with a stored list. The infotainment control module (ICM) retrieves data about the serial number of the control modules via the MOST network. The infotainment control module (ICM) compares the information with the stored serial numbers.
If a control module is not in the stored list, it is disconnected from the MOST network and the functionality of this control module is blocked. This means that control modules in the MOST network cannot be moved from one vehicle to another.
A diagnostic trouble code (DTC) is stored in the infotainment control module (ICM) if a control module in the stored list gives the incorrect response.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.