
235
4
4-2. Driving procedures
Driving
GS450h_300h_OM_OM30F92E_(EE)
Brake Hold
Turns the brake hold system on
The brake hold standby indicator
(green) comes on. While the system is holding the brake, the brake hold oper-ated indicator (yellow) comes on.
■Brake hold system operating conditions
The brake hold system cannot be turn ed on in the following conditions:
●The driver’s door is not closed.
●The driver is not wearing the seat belt.
●“EPB Activation Stopped Incompletely” or “Electronic Parking Brake Malfunction Visit Your Dealer” is displayed on the multi-information display.
If any of the conditions above are detected when the brake hold system is enabled, the system will turn off and the brake hold standby indicator light will go off. In addition, if any of the conditions are detected while the sy stem is holding the brake, a warning buzzer
will sound and a message will be shown on th e multi-information display. The parking brake will then be set automatically.
■Brake hold function
●If the brake pedal is left released for a pe riod of about 3 minutes after the system has started holding the brake, th e parking brake will be set automatically. In this case, a warning buzzer sounds and a message is shown on the multi-information display.
●To turn the system off while the system is holding the brake, firmly depress the brake pedal and press the button again.
●The brake hold function may not hold the vehicle when the vehicle is on a steep incline.
In this situation, it may be necessary for the driver to apply the brakes. A warning buzzer will sound and the multi-information disp lay will inform the driver of this situa- tion. ( P. 466)
The brake hold system keeps the brake applied when the shift lever is in D, S or
N with the system on and the brake peda l has been depressed to stop the vehi-
cle. The system releases the brake when the accelerator pedal is depressed
with the shift lever in D or S to allow smooth start off.

2364-2. Driving procedures
GS450h_300h_OM_OM30F92E_(EE)
■When the parking brake is set automatically while the system is holding the brakes
The parking brake will not be released auto matically. Perform one of the following proce- dures to release the parking brake and conf irm that the parking brake indicator light
turns off. ( P. 232)
●With the brake pedal depressed, operate the parking brake switch.
●Fasten your seat belt, check that the shift lever is in either D or R and slowly depress the
accelerator pedal.
■Warning message and buzzers
Warning messages and buzzers are used to indicate a system malfunction or to inform
the driver of the need for caution. ( P. 466)
WARNING
■When the vehicle is on a steep incline
When using the brake hold system on a steep incline exercise caution. The brake hold function may not hold the vehicle in such a situation.
■When stopped on a slippery road
The system cannot stop the vehicle when the gripping ability of the tires has been exceeded. Do not use the system when stopped on a slippery road.
NOTICE
■When parking the vehicle
The brake hold system is not designed fo r use when parking the vehicle for a long
period of time. Turning the power switch o ff while the system is holding the brake may release the brake, which would cause the vehicle to move. When operating the powerswitch, depress the brake pedal, set the pa rking brake and shift the shift lever to P.

3054-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
■Dynamic radar cruise control with full-speed range can be set when
●The shift lever is in D or range 4 or higher of S has been selected.
●Range 4 or higher of D has been selected by using the paddle shift switch.
●Vehicle speed is above approximately 50 km/h (30 mph).
However, when a preceding vehicle is dete cted, the dynamic radar cruise control with full-speed range can be set even if the vehicle speed is at or below approximately50 km/h (30 mph).
■Accelerating after setting the vehicle speed
The vehicle can accelerate by operating the accelerator pedal. After accelerating, the set speed resumes. However, during vehicle- to-vehicle distance control mode, the vehi-
cle speed may decrease below the set speed in order to maintain the distance to the pre- ceding vehicle.
■Automatic cancelation of vehicle -to-vehicle distance control mode
Vehicle-to-vehicle distance control mode is automatically canceled in the following situ- ations.
●Actual vehicle speed falls below approximat ely 40 km/h (25 mph) when there are no
vehicles ahead.
●The preceding vehicle leaves the lane when your vehicle is following at a vehicle speed below approximately 40 km/h (25 mph). Otherwise, the sensor can not properly
detect the vehicle.
●VSC is activated.
●TRC is activated for a period of time.
●When the VSC or TRC system is turned off by pressing the VSC OFF switch.
●When snow mode is set.
●The sensor cannot detect correctly because it is covered in some way.
●Pre-crash braking is activated.
●The parking brake is operated.
●The vehicle is stopped by syst em control on a steep incline.
●The following are detected when the vehicle has been stopped by system control:
• The driver is not wearing a seat belt. • The driver’s door is opened.
• The vehicle has been stopped for about 3 minutes If vehicle-to-vehicle distance control mode is automatically canceled for any other rea-son, there may be a malfunction in the syst em. Contact any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer.

3284-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
■Sounds and vibrations caused by the ABS, brake assist, VSC, Hill-start assist control, TRC and VGRS systems
Any of the following conditions may occur when the above systems are operating. None
of these indicates that a malfunction has occurred.
●Vibrations may be felt through the vehicle body and steering.
●A motor sound may be heard after the vehicle comes to a stop.
■ECB operation sound
ECB operating sound may be heard in the follow ing cases, but it does not indicate that a malfunction has occurred.
●Operating sound heard from the engine compartment when the brake pedal is oper-ated.
●Motor sounds of the brake system heard from the front part of the vehicle when the
driver’s door is opened.
●Operating sound heard from the engine compartment when one or two minutes passed after the stop of the hybrid system.
■EPS, VGRS and DRS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard. This does not indicate a malfunction.
■Automatic reactivation of TRC and VSC systems
After turning the TRC and VSC systems off, the systems will be automatically re-enabled in the following situations:
●When the power switch is turned off
●If only the TRC system is turned off, the TR C will turn on when vehicle speed increases If both TRC and VSC systems are turned off, automatic re-enabling will not occur when
vehicle speed increases.
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheating when there is frequent steering input over an extended period of time. The steeringwheel may feel heavy as a result. Should this occur, refrain from excessive steering input
or stop the vehicle and turn the hybrid system off. The EPS system should return to nor- mal within 10 minutes.
■Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will operate;
●The shift lever is in a position other than N or P (when starting off forward/backward on an upward incline).
●The vehicle is stopped.
●The accelerator pedal is not depressed.
●The parking brake is not engaged.

3294-5. Using the driving support systems
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
■Automatic system cancelation of hill-start assist control
The hill-start assist control will be canc eled in any of the following situations;
●The shift lever is shifted to N or P.
●The accelerator pedal is depressed.
●The parking brake is engaged.
●Approximately 2 seconds elapse after the brake pedal is released.
■Operating conditions of emergency brake signal
When the following three conditions are me t, the emergency brake signal will operate:
●The emergency flashers are off.
●Actual vehicle speed is over 55 km/h (35 mph).
●The brake pedal is depressed in a manner that cause the system to judge from the vehi- cle deceleration that this is a sudden braking operation.
■Automatic system cancelation of emergency brake signal
The emergency brake signal will turn of f in any of the following situations:
●The emergency flashers are turned on.
●The brake pedal is released.
●The system judges from the vehicle deceleration that is not a sudden braking operation.
WARNING
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded (such as excessively
worn tires on a snow covered road).
●The vehicle hydroplanes while driving at high speed on wet or slick roads.
■Stopping distance when the ABS is operating may exceed that of normal conditions
The ABS is not designed to shorten the vehicle’s stopping distance. Always maintain a safe distance from the vehicle in front of you, especially in the following situations:
●When driving on dirt, gravel or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or uneven surfaces
■TRC may not operate effectively when
Directional control and power may not be achievable while driving on slippery road surfaces, even if the TRC system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost.
■Hill-start assist control does not operate effectively when
●Do not overly rely on the hill-start assist control. The hill-start assist control may not
operate effectively on steep inclines and roads covered with ice.
●Unlike the parking brake, hill-start assist co ntrol is not intended to hold the vehicle stationary for an extended period of time. Do not attempt to use hill-start assist con-
trol to hold the vehicle on an incline, as doing so may lead to an accident.

331
4
4-6. Driving tips
Driving
GS450h_300h_OM_OM30F92E_(EE)
Hybrid vehicle driving tips
◆Using Eco drive mode
When using Eco drive mode, the torque corresponding to the accelerator
pedal depression amount can be generate d more smoothly than it is in normal
conditions. In addition, the operation of the air conditioning system (heating/
cooling) will be minimized, improving the fuel economy. ( P. 311)
◆Use of Hybrid System Indicator
The Eco-friendly driving is possible by keeping the indicate of Hybrid System
Indicator within Eco area. ( P. 108, 123)
◆Shift lever operation
Shift the shift lever to D when stopped at a traffic light, or driving in heavy traf-
fic etc. Shift the shift lever to P when parking. When using the N, there is no
positive effect on fuel consumption. In the N, the gasoline engine operates but
electricity cannot be generated. Also, when using the air conditioning system,
etc., the hybrid battery (traction battery) power is consumed.
◆Accelerator pedal/brake pedal operation
●Drive your vehicle smoothly. Avoid abrupt acceleration and deceleration.
Gradual acceleration and deceleration will make more effective use of the
electric motor (traction motor) without having to use gasoline engine
power.
●Avoid repeated acceleration. Repeated acceleration consumes hybrid bat-
tery (traction battery) power, resulting in poor fuel consumption. Battery
power can be restored by driving with the accelerator pedal slightly
released.
◆When braking
Make sure to operate the brakes gently and in a timely manner. A greater
amount of electrical energy can be regenerated when slowing down.
For economical and ecological driving, pay attention to the following points:

3354-6. Driving tips
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
Accelerate the vehicle slowly, keep a safe distance between you and the vehicle
ahead, and drive at a reduced speed suitable to road conditions.
●Park the vehicle and move the shift lever to P without setting the parking
brake. The parking brake may freeze up, preventing it from being released. If
the vehicle is parked without setting the parking brake, make sure to block the
wheels.
Failure to do so may be dangerous because it may cause the vehicle to move
unexpectedly, possibly leading to an accident.
●If the vehicle is parked without setting the parking brake, confirm that the shift
lever cannot be moved out of P*.
*: The shift lever will be locked if it is attemp ted to be shifted from P to any other position
without depressing the brake pedal. If the shift lever can be shifted from P, there may
be a problem with the shift lock system. Have the vehicle inspected by any authorized
Lexus retailer or Lexus authorized repair er, or any reliable repairer immediately.
When driving the vehicle
When parking the vehicle

451
7When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
7-1. Essential information
Emergency flashers ..................452
If your vehicle has to be
stopped in an
emergency.................................453
7-2. Steps to take in an
emergency
If your vehicle needs
to be towed................................ 454
If you think something
is wrong....................................... 459
If a warning light turns on
or a warning buzzer
sounds..........................................460
If a warning message
is displayed ................................ 466
If you have a flat tire
(vehicles with spare tire) ......498
If you have a flat tire
(vehicles without spare
tire)................................................509
If the hybrid system
will not start................................ 523
If the parking brake
cannot be released................. 525
If the electronic key does
not operate properly ............. 527
If the 12-volt battery is
discharged .................................530
If your vehicle overheats .........535
If the vehicle becomes
stuck ............................................. 542