Testing For False Alarms

Information and verification, alarm

Symptom and function description
Central electronic module (CEM) is the main module for the alarm functions. When a locking command is received by the Central electronic module (CEM), the Central electronic module (CEM) will first lock the central locking system and then activate the alarm. A long flashing signal, from the vehicle's direction indicators, confirms that the alarm is activated and that the doors are locked. The alarm LED will start to flash directly after the system has been activated. How the vehicle confirms that the alarm is activated can be adapted to the customer's wishes by programming the Infotainment control module (ICM).
The alarm should trip when:
- Door, bonnet or boot lid are opened.
- A non-approved key is used in the keyhole or if the key has been tampered with.
- Movement detected in the passenger compartment (only applies if the vehicle is equipped with a movement sensor).
- The vehicle is lifted or towed away (only applies if the vehicle is equipped with a level movement sensor).
- Someone attempts to disconnect the siren or battery.
- The panic function is activated via the remote key.

Hint: For more information, see Design and Function.

Note! If a vehicle gives a false alarm this can be due to:
- Alarm system failure.
- That different layers of air form in the vehicle's passenger compartment on account of changes in temperature. The alarm can trip when the layers of air begin to move in the passenger compartment.

Verification
If the customer experiences frequent false alarms it is advisable to let a mechanic fault trace the system.

Is the function OK?

Yes - No Fault Found

No - FAULT FOUND

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