Dynamic Radar Cruise Control

The Dynamic Radar Cruise Control chapter of the Lexus GS L10 explains the technical sophistication of the system. It describes how speed and distance are regulated automatically and which warnings the driver should observe to ensure maximum safety. It also provides recommendations for optimal use of the two modes, distance control mode and constant speed control mode, as well as clear warnings about situations in which the system should not be used to avoid accidents.

Summary of Functions

In distance control mode, the vehicle accelerates and brakes automatically to adjust its speed to changes in the speed of the vehicle ahead, even when the accelerator pedal is not depressed. In constant speed control mode, the vehicle travels at a set speed.

Use Dynamic Radar Cruise Control on motorways and expressways.

• Distance control mode
• Constant speed control mode

GS350/GS200t

GS F

1. 1
   Distance control system button
2. 2
   Display
3. 3
   Set speed
4. 4
   Warning lights
5. 5
   Cruise control switch

WARNING

■ Before using Dynamic Radar Cruise Control

As the driver, you alone are responsible for safely operating your vehicle. Do not rely solely on the system. Drive carefully and always keep a close watch on your surroundings.

Dynamic Radar Cruise Control assists the driver to reduce driving workload. However, the assistance the system can provide is limited.

Even when the system is operating normally, it may assess the condition of the vehicle ahead differently than you do. For this reason, you must always remain attentive as the driver, judge the hazards of every situation yourself and drive cautiously.

If you rely solely on this system or assume that the system guarantees driving safety, an accident resulting in death or serious injury may occur.

■ Precautions regarding the driver assistance systems

Because the assistance provided by the system has its limits, observe the following precautions.

Otherwise, an accident resulting in death or serious injury may occur.

• Assistance in judging the distance to the vehicle ahead. Dynamic Radar Cruise Control is intended solely to assist the driver in judging the distance between your vehicle and a vehicle directly ahead. It is not a device that permits careless or inattentive driving, and the system cannot assist the driver in situations with limited visibility. The driver must always remain attentive to the road and the area around the vehicle.
• Assists the driver in judging an appropriate following distance. The Dynamic Radar Cruise Control checks whether the distance between your vehicle and the vehicle directly ahead is within a set range. It cannot assess anything else. The driver must therefore remain attentive at all times and decide for themselves whether a particular situation involves a hazard.
• Assists with vehicle operation. The Dynamic Radar Cruise Control is only able to prevent a collision with a vehicle ahead to a limited extent. If there is a risk of collision, the driver must react immediately and appropriately to ensure the safety of everyone involved.

■ How to prevent unintentional activation of the Dynamic Radar Cruise Control

Turn the Dynamic Radar Cruise Control off using the "ON/OFF" switch when it is not in use.

WARNING

■ Situations for which the Dynamic Radar Cruise Control is not suitable

Do not use the Dynamic Radar Cruise Control in the following situations.

Otherwise, the vehicle speed may not be controlled appropriately for the situation, which may result in an accident causing death or serious injury.

• On roads where pedestrians, cyclists, etc. are present
• In heavy traffic
• On roads with sharp curves
• On winding mountain roads
• On slippery road surfaces, e.g. in rain, ice or snow
• On roads with steep gradients, or roads with frequently changing steep uphill and downhill sections. The actual speed may exceed the set speed when driving steeply downhill.
• At motorway or expressway entrance ramps
• In weather conditions so poor that the sensors may not detect correctly (fog, snow, sandstorms, heavy rain, etc.)
• When water, snow, etc. is on the front surface of the radar sensor or camera sensor
• When traffic conditions require frequent acceleration and braking
• When towing a trailer or providing towing assistance with your vehicle
• When the distance warning buzzer sounds frequently

Driving in distance control mode

In this mode, the radar sensor detects vehicles ahead at distances of up to approx. 120 m (394 ft.). The current distance to the vehicle ahead is determined, and an appropriate following distance is maintained.

Note that the vehicle-to-vehicle distance decreases during long downhill driving.

1. 1
   Example of driving at a constant speed.

   When there are no vehicles ahead of you.

   The vehicle travels at the speed set by the driver. The desired vehicle-to-vehicle distance can also be set by pressing the distance control system button.

2. 2
   Example of decelerating and following.

   When a vehicle appears ahead that is traveling slower than the speed you have set.

   When a vehicle ahead is detected, the system automatically decelerates your vehicle. If a greater reduction in speed is required, the system applies the brakes (the brake lights illuminate in this case). The system responds to changes in the speed of the vehicle ahead to maintain the vehicle-to-vehicle distance you have set. The distance warning alerts you when the system cannot decelerate sufficiently to prevent you from getting too close to the vehicle ahead.

3. 3
   Example of accelerating.

   When there are no longer any vehicles ahead traveling slower than the set speed.

   The system accelerates the vehicle to the set speed. The system then returns to constant speed driving.

Setting the speed (distance control mode)

1. 1
   Press the "ON/OFF" button to turn on the cruise control.

   The radar cruise control indicator light illuminates and a message is shown on the multi-information display.

   Press the button again to turn off the cruise control.

   If you press and hold the "ON/OFF" button for at least 1.5 seconds, the system switches to constant speed control mode.

2. 2
   Accelerate or decelerate to the desired speed using the accelerator pedal (more than approx. 50 km/h), then push the lever down to set the speed.

   The "SET" indicator light for the cruise control then illuminates.

   Control is set to the speed you are driving at when you release the lever.

   

Changing the Set Speed

Operate the lever until the desired speed is displayed.

1. 1
   Increase speed
2. 2
   Decrease speed

Fine adjustment: Briefly move the lever in the desired direction.

Coarse adjustment: Move the lever up or down and hold it until the desired speed is reached.

In distance control mode, the set speed is increased or decreased as follows:

• Europe

Fine adjustment: Each lever operation changes the set speed by 5 km/h*1 or 8 km/h*2. Coarse adjustment: Increase or decrease in steps of 5 km/h*1 or

8 km/h*2 while the lever is held down

• Except Europe

Fine adjustment: Each lever operation changes the set speed by 1 km/h*1 or 1.6 km/h*2. Coarse adjustment: Increase or decrease in steps of 5 km/h*1 or

8 km/h*2 while the lever is held down

In constant speed control mode, the set speed is increased or decreased as follows: Fine adjustment: Each lever operation changes the speed by 1 km/h*1 or 1.6 km/h*2. Coarse adjustment: The speed changes while the lever is held.

*1: When the set speed is displayed in "km/h"

*2: When the set speed is displayed in "MPH"

Changing the vehicle-to-vehicle distance (distance control mode)

GS350/GS200t

GS F

Press the button to change the vehicle-to-vehicle distance as follows:

1. 1
   Long
2. 2
   Medium
3. 3
   Short

The vehicle-to-vehicle distance is automatically set to "Long" when the ignition switch is turned to IGNITION ON mode.

If a vehicle is ahead of you, the vehicle ahead indicator is also displayed.

Vehicle-to-Vehicle Distance Settings (Distance Control Mode)

Select a distance from the table below. Note that the distances shown are based on a speed of 80 km/h.

The vehicle-to-vehicle distance increases/decreases depending on the speed.

Canceling and Resuming Cruise Control

1. 1
   Pull the lever toward you to cancel cruise control.

   Cruise control is also canceled when the brake pedal is depressed.

2. 2
   Push the lever up to resume cruise control. The previously set speed will be resumed.

   However, cruise control will not resume if the speed is approx. 40 km/h or less.

Distance Warning (Distance Control Mode)

If your vehicle is too close to the vehicle ahead and sufficient automatic braking cannot be achieved by cruise control, the indicator will flash and a warning buzzer will sound to alert you.

An example of this is when another vehicle cuts in between your vehicle and the vehicle ahead.

Depress the brake pedal to ensure an adequate vehicle-to-vehicle distance.

■ Conditions Under Which Warnings May Not Be Issued

In the following situations, a warning may not be issued even though the vehicle-to-vehicle distance is short.

• When the vehicle ahead is traveling at the same speed as or faster than you
• When the vehicle ahead is traveling extremely slowly
• Immediately after setting the cruise control set speed
• When the accelerator pedal is depressed

Selecting Constant Speed Control Mode

When you select constant speed control mode, the vehicle maintains the set speed without controlling the vehicle-to-vehicle distance. Select this mode only when distance control mode is not functioning properly due to contamination of the radar sensor, etc.

1. 1
   While cruise control is off, press and hold the "ON/OFF" switch for at least 1.5 seconds.

   Immediately after pressing the "ON/OFF" switch, the radar cruise control indicator light comes on.

   Then, this light turns off and the cruise control indicator light comes on.

   Switching to constant speed control mode by operating the lever is only possible when cruise control is off.

2. 2
   Accelerate or decelerate to the desired speed using the accelerator pedal (more than approx. 50 km/h), then push the lever down to set the speed.

   The "SET" indicator light for the cruise control then illuminates.

   Control is set to the speed you are driving at when you release the lever.

   

■ Conditions for activating the Dynamic Radar Cruise Control

• The shift lever is in "D".
• The gear selector switch has been used to select a range of "4" or higher from "D".
• The speed is above approx. 50 km/h.

■ Accelerating After the Speed Has Been Set

The vehicle can be accelerated by depressing the accelerator pedal. After accelerating, the set speed will be resumed. However, when distance control mode is active, the speed may drop below the set speed in order to maintain the distance to the vehicle ahead.

■ Automatic Cancellation of Distance Control Mode

Distance control mode is automatically canceled in the following situations.

• The actual speed drops below approximately 40 km/h.
• VSC is activated.
• TRC is activated for a certain period of time.
• The VSC or TRC system is turned off by pressing the VSC OFF switch.
• SNOW mode is selected.
• The sensor's detection capability is impaired because it is obstructed.
• The Pre-Collision System is activated.

If distance control mode is automatically canceled for any other reason, a malfunction of the system may exist. Contact your Lexus dealer or repairer, or another qualified and properly equipped repair facility.

■ Automatic Cancellation of Constant Speed Control Mode

Constant speed control mode is automatically canceled in the following situations:

• The actual speed is more than approximately 16 km/h below the set speed.
• The actual speed drops below approximately 40 km/h.
• VSC is activated.
• TRC is activated for a certain period of time.
• The VSC or TRC system is turned off by pressing the VSC OFF switch.
• The Pre-Collision System is activated.

If the constant speed control mode is canceled automatically for any other reason, there may be a malfunction in the system. Contact a Lexus dealer or authorized repairer, or another qualified and properly equipped repair facility.

■ Warning messages and warning buzzer of the Dynamic Radar Cruise Control

Warning messages and warning buzzers indicate a malfunction in the system or alert the driver that extra caution is required while driving. If a warning message appears on the multi-information display, read it and follow the instructions.

■If the sensor may not correctly detect the vehicle ahead of you

In the following situations, you may need to depress the brake pedal if the braking provided by the system is not sufficient, or depress the accelerator pedal if acceleration is required.

Because the sensor may not be able to detect these vehicles correctly, the distance warning may not activate.

• Vehicles that suddenly cut in
• Vehicles traveling slowly
• Vehicles that are not in the same lane
• Vehicles with a small rear surface area (unloaded trailers, etc.)
• 
• Motorcycles traveling in the same lane
• When detection by the sensor is obstructed by water or snow thrown up by other vehicles
• When your vehicle is tilted upward (due to a heavy load in the luggage compartment, etc.)
• The vehicle ahead has extremely high ground clearance

■ Conditions under which the distance control mode may not operate correctly. In the following situations, depress the brake pedal (or, depending on the circumstances, the accelerator pedal) as required.

Because the sensor may not be able to correctly detect vehicles ahead of your vehicle, the system may not operate properly.

• When the road is winding or the lanes are narrow
• When your steering inputs or your position in the lane are not stable
• When the vehicle ahead suddenly decelerates

The Dynamic Radar Cruise Control in the fourth-generation Lexus GS is ideal for long motorway journeys. It combines comfortable driving with intelligent technology and helps the driver maintain a safe distance from the vehicle ahead. The system offers both a distance control mode and a constant speed mode for different driving situations.

Precise control and simple operation make driving the Lexus GS GRL1 (2016–2020) more comfortable and safer. The sport sedan impresses with state-of-the-art driver assistance systems that noticeably ease everyday driving.

When should I use the constant speed mode?

This mode is suitable when the radar sensor is impaired, e.g. by dirt, and distance control mode is not possible.

Can the set speed be adjusted at any time?

Yes, the speed can be adjusted at any time using the lever, in fine or coarse steps.