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.
The siren is used as the sound source for the alarm function. The siren includes an internal battery which is charged when the lights are on. The climate affects the life of the battery. Consequently the siren should be replaced at regular intervals.
Remote key includes an internal battery. When the battery in the remote key runs down a message is shown on the driver information module (DIM). Another indication that the remote key's battery is running down is a reduction in the remote key's range.
Verification
Check the different alarm system functions as follows:
The alarm shall trip during each test, a siren shall sound and all direction indicators flash. It should be possible to deactivate the alarm using the remote key's unlock button or by inserting the remote key in the starter switch. A signal confirming alarm deactivation must be given by the direction indicators (two short flashes).
Testing the doors
- Open all windows.
- Deactivate the movement sensor, then activate the alarm.
- Wait 30 seconds.
- Open one of the doors by using the handle on the inside of the door.
Testing the hood
- Sit in the vehicle.
- Deactivate the movement sensor, then activate the alarm.
- Wait 30 seconds.
- Open the bonnet with the handle below the instrument panel.
Test of automatic activation (market dependent)
- Activate the alarm.
- Wait 30 seconds.
- Deactivate the alarm with the remote key. Do not open the doors or hoods.
- Wait two minutes. The vehicle shall automatically activate the alarm and lock the doors.