Scan Tool Testing and Procedures

Description of alarm cause readout

The data is read out as follows:

Alarm cause
Indicates the component in the vehicle that caused the alarm.
- Front door right
- Front door left
- Right rear door (for C30: wire for manipulation protection)
- Left rear door (for C30: glass breakage wire in rear window)
- Hood
- Trunk lid/tailgate
- Ignition switch
- Vehicle tilt sensor
- Siren
- MMS 1, standard mass movement sensor module (MMS) for coupe models. Front mass movement sensor module (MMS)
- MMS 2, only available in station wagon models. Rear mass movement sensor module (MMS).

Alarm status, fault in mass movement sensor (MMS)
The parameter indicates whether a fault has occurred in the communication with the mass movement sensor(s) (MMS) in the vehicle.
The parameter can assume the values:
True=a fault has occurred which means that the mass movement sensors (MMS) are not responding.
False=no fault has been discovered.

Alarm status, fault in vehicle tilt sensor
The parameter indicates whether a fault has occurred in communication with the vehicle tilt sensor in the siren.
True=a fault has been discovered.
False=no fault has been discovered.

Alarm status, fault in siren
The parameter indicates whether a fault has occurred in the siren.
True=a fault has been discovered in the siren.
False=no fault has been discovered.

Alarm status
The parameter indicates the status of the alarm system.
The parameter can assume the following values:
- Activated
- Deactivated
- Deployed.

Alarm cause, table
The most recent alarm causes can be read off using this function.
The 15 most recent alarm causes can be read off for older vehicles.

Note! The readout is not necessarily in chronological order. The list is filled in from top to bottom. When full, the alarm cause listings start from the top of the list again.

The functionality for the list is different on older model years.
On newer vehicles, the number of alarm causes has been reduced to 9. The first item in the readout list is a counter indicating where in the list the next alarm cause will be entered. The counter runs from 0 to 7 as the rows are counted from 0 to 7. If the counter indicates 2, the next alarm cause will be entered at the third row. In this example, the latest alarm cause is the second from the top of the list. When the list is full, the system starts over (i.e. at the top of the list) when entering alarm causes.
The causes of the activated alarms may be one of the following.
- Not triggered
- Voltage drop siren
- Vehicle tilt sensor
- Mass movement sensor (MMS), front
- Mass movement sensor (MMS), rear
- Driver's door
- Passenger door
- Left rear door

Note! Not C70. For C30, this is the alarm cause for the glass breakage wire in the rear window.

- Right rear door

Note! Not C70. For C30, this is the alarm cause for the manipulation protection for the cable harness in the trunk lid.

- Trunk lid / Tailgate
- Hood
- No communication.
- Start attempts.