Locking and Alarm Systems (page 9 of 9)

SECURITY

86-5-12 DESCRIPTION AND OPERATION

Tilt Sensor
The tilt sensor monitors for changes of vehicle attitude while the alarm is armed. The tilt sensor is installed under the 
passenger seat in the BCU bracket.

The tilt sensor incorporates a two axis sensor controlled by a microprocessor. A permanent battery feed from the 
passenger compartment fusebox powers the tilt sensor. The BCU activates and de-activates the tilt sensor when it 
arms and disarms the alarm system. The tilt sensor receives activation and de-activation signals from the BCU.

The tilt sensor measures the longitudinal and transverse angles of the vehicle over a range of 

±

16

°

 from the horizontal. 

When the tilt sensor is activated, it stores the current angles in memory. If the vehicle changes attitude in either 
direction by more than the limit the tilt sensor sends an alarm signal to the BCU, which triggers the BBUS. After an 
alarm, the alarm limit is reduced to make the system more sensitive to any further change of attitude.

Alarm Triggering Limits

Each time the tilt sensor is activated it performs a self test. If there are no faults the tilt sensor sends an 
acknowledgement signal to the BCU. If the BCU does not receive the acknowledgement signal it de-activates the tilt 
sensor.

Tilt Sensor Harness Connector

Tilt Sensor Harness Connector C0960 Pin Details

Alarm

Limit, Degrees

Longitudinal

Transverse

First alarm

1.2 

±

 0.55

1.4 

±

 0.55

Second alarm

1.1 

±

 0.55

1.3 

±

 0.55

Pin No.

Description

Input/Output

1

Alarm indication

Output

2

Arm/Disarm signal

Output

3

Battery power supply

Input

4

Arm/Disarm signal

Input

5

Arm/Disarm signal

Output

6

Not used

–

M86 5981

C0960