Interior Protection (Convertible)

Interior Protection

The interior protection system is based on a movement detector (microwaves) that detects movements in the vehicle interior and sends corresponding signals to the ZKE general module.

On the E46 Convertible, there are two interior protection system control modules fitted (1 and 2, front and rear); on the E52 Z8, a control module for radio-controlled surveillance of interior is fitted; and on the E85 Z4 an interior protection system is fitted. The front control module is located under the center console behind the gearshift lever/selector lever. The rear control module is fitted under the rear seat.

Function

Passenger compartment (interior) monitoring
A transmitter antenna is integrated in the interior protection system control module and radio-control surveillance of interior for the purpose of generating an electromagnetic field in the vehicle. The reflections are received by the receiving antenna in the control module and transferred to the integrated electronic circuitry for evaluation.

Movements in the vehicle cause a change in the reflections and trigger an alarm via the central body electronics control module (ZKE).

Notes on operation
For insurance reasons (depending on national legislation), all windows must be closed at all times also when the convertible top is open. This requirement also reduces the risk of a false alarm, e.g. by persons leaning on the car.

Large metal objects (e.g. metal case) shield the electromagnetic waves so that in certain areas no alarm can be recognized due to shadow effects.

When the convertible top is open, an alarm may be triggered in the following instances:
- Precipitation (rain, snow, hail etc..)
- Objects that drop into the car (leaves, branches etc..)
- Animals that enter the vehicle (dogs, cats, birds, etc..)
- People who lean on or reach into the car

Alarm triggering
The alarm triggering is stored in the alarm menu of the body electronics control module. A distinction is made whether the front control module (display: interior protection 1) or the rear control module (display: interior protection 2) triggered the alarm.

Activation/deactivation
When the antitheft alarm system is armed, the interior monitoring facility is activated by the ZKE general module via the STDWA line and deactivated when the system is disarmed (the same line also activates and deactivates the tilt alarm sensor and siren).

Interior monitoring begins 30 seconds after activating the antitheft alarm system. The interior is not monitored when a vehicle door or the luggage compartment lid is open. Opening the luggage compartment lid or convenience closing of the windows interrupts the interior protection function.

If the interior protection system control module detects a triggered alarm, this status is signaled to the general module via the INRS or INRS2 (interior protection system control module 2) line.

In order to avoid false alarms being triggered under unfavorable ambient conditions, the interior protection function can be switched off with the antitheft alarm system activated as follows:
- Activate antitheft alarm system via door lock or remote control
- Repeat activating procedure within 10 seconds

Self test
After the antitheft alarm system has been activated, the interior protection system control module runs a self test. If a fault occurs here, this status is signaled to the general module of the ZKE via the INRS (interior protection system control module 1) or INRS2 (interior protection system control module 2) line. A fault code for defective interior protection is stored in the general module (display: interior protection 1 / interior protection 2).

A faulty module is not activated in order to avoid false alarms being triggered.