Theft Deterrent System. Alarm System

The alarm system of the Lexus GS (L10) provides comprehensive protection through audible and visual warning signals. It responds to unauthorized opening of the doors, trunk or hood, as well as to tilt or intrusion sensors (if equipped). This chapter explains how the system works, how to activate and deactivate it, and provides important information on how to avoid false alarms, for example by closing all windows and removing movable objects from the interior.

The Alarm System

The alarm system warns with a light and a sound signal when an intrusion is detected.

When the alarm system is set, the alarm will be triggered in the following situations:

• A locked door is unlocked or opened by any means other than the smart access function or the remote transmitter. (The door will automatically lock again.)
• The trunk is opened by any means other than the smart access function, the remote transmitter, or the mechanical key.
• The hood is opened.
• The tilt sensor detects a change in the vehicle's tilt angle. (If equipped)

Setting the Alarm System

Close the doors, trunk and hood, and lock all doors using the smart access function or the remote transmitter.

The alarm system is set automatically after 30 seconds.

The indicator light changes from steady on to flashing when the alarm system is set.

Deactivating or Canceling the Alarm

Perform one of the following steps to deactivate or cancel the alarm:

• Unlock the doors or open the trunk using the smart access function or the remote transmitter.
• Switch the engine switch to ACCESSORY or IGNITION ON mode, or start the engine. (The alarm is deactivated or canceled after a few seconds.)

System maintenance

The vehicle is equipped with a maintenance-free alarm system.

Items to Check Before Locking the Vehicle

To prevent the alarm from being triggered accidentally and to protect the vehicle against theft, make sure of the following:

• No one is inside the vehicle.
• The windows and sunroof (if equipped) are closed before the alarm system is set.
• There are no valuables or other personal items inside the vehicle.

Triggering the Alarm

The alarm may be triggered in the following situations. (Canceling the alarm deactivates the alarm system.)

• The doors are unlocked with the mechanical key, or the trunk is opened with the mechanical key.
• A person inside the vehicle opens a door, the trunk or the hood, or unlocks the vehicle using an interior door lock switch.
• The battery is charged or replaced while the vehicle is locked.

Door Locking Activated by the Alarm System

The door may lock automatically in the following cases:

• When a person remaining inside the vehicle unlocks the door and the alarm is set.
• When a person remaining inside the vehicle unlocks the door while the alarm is set.
• When charging or replacing the battery.

Customization

You can set the alarm system so that it is deactivated when the mechanical key is used to unlock the vehicle.

NOTE

Ensuring the System Operates Properly

Do not modify or disassemble the system. If the system is modified or removed, its proper operation cannot be guaranteed.

Intrusion Sensor (if equipped) and Tilt Sensor (if equipped)

• The intrusion sensor detects intruders and movement inside the vehicle.
• The tilt sensor detects changes in the vehicle's tilt angle, such as when the vehicle is being towed.

This system is designed to protect the vehicle against theft, but it does not provide absolute protection against break-ins.

Activating the Intrusion Sensor and Tilt Sensor

The intrusion sensor and tilt sensor are activated automatically when the alarm system is set.

Deactivating the Intrusion Sensor and Tilt Sensor

If you leave animals or movable items in the vehicle, make sure to turn off the intrusion sensor and tilt sensor before arming the alarm system, as they respond to movement inside the vehicle.

1. 1
   Turn the engine switch off.
2. 2
   Press the intrusion sensor and tilt sensor deactivation switch.

   

A message appears on the multi-information display in the instrument cluster.

Press the switch again to reactivate the intrusion sensor and tilt sensor.

Deactivation and Automatic Reactivation of the Intrusion Sensor and Tilt Sensor

• The alarm system remains armed even when the intrusion sensor and tilt sensor have been deactivated.
• After the intrusion sensor and tilt sensor have been deactivated, they can be reactivated by pressing the engine switch or by unlocking the doors with the smart access function, the remote control or the mechanical key.
• The intrusion sensor and tilt sensor are automatically reactivated when the alarm system is disarmed.

Notes on Intrusion Sensor Detection (if equipped)

The sensor may trigger the alarm in the following situations:

• A window or the sunroof (if equipped) is open.

  In this case, the sensor may detect the following:

Wind or movement of leaves, insects, etc. inside the vehicle
Ultrasonic waves emitted, for example, by intrusion sensors of other vehicles
Movement of people outside the vehicle

• Unstable objects, such as hanging accessories or clothing hung on grab handles inside the vehicle.
• In locations with extreme vibration or loud noise, or in situations where the vehicle is repeatedly subjected to impacts or vibration:

When the vehicle is parked in a parking garage
When the vehicle is transported on a ferry, trailer, train, etc.
When ice adhering to the vehicle is being removed
When the vehicle is in an automatic car wash or high-pressure car wash
During hail or thunderstorms

Notes on Tilt Sensor Detection (if equipped)

The sensor may trigger the alarm in the following situations:

• The vehicle is being transported on a ferry, trailer, train, etc.
• The vehicle is parked in a multi-storey car park.
• The vehicle is in a car wash that moves the vehicle along.
• One of the tires is losing pressure.
• The vehicle is being jacked up.
• In the event of an earthquake or road subsidence.

NOTE

Ensuring the Intrusion Sensor Works Properly

• To ensure the sensors function correctly, do not touch or cover them.
• Do not spray air fresheners or other products directly into the sensor openings.
• Installing accessories other than genuine Lexus accessories, or leaving objects between the driver and front passenger seats, may impair detection performance.

The alarm system in the Lexus GS (4th generation) provides comprehensive protection against break-in and theft. It combines visual and audible signals with modern sensors that detect movement or changes in inclination. This way, any unauthorized access to the vehicle is reported immediately and potential thieves are deterred.

Particular emphasis has been placed on simple activation and deactivation of the system so that daily operation remains convenient. With this technology, Lexus demonstrates that security and ease of use go hand in hand.