2014 PORSCHE 911 TURBO brake

154 Driving and Driving Safety
fBefore descending a steep grade, reduce speed and shift the transmission into a lower gear to control speed. fDo not “ride the brakes” by resting your foot on the pedal when not intending to apply brake pressure.fDo not hold the pedal down too long or too often. This could cause the brakes to overheat and lose braking power.
Brake booster
The brake booster assists braking only when the engine is running.
When the car is moving while the engine is not running, or if the brake booster is defective, more pressure on the brake pedal is required to bring the car to a stop.
Moisture, road salt or grit on brakes affects braking. Brakes will dry after a few cautious brake applications.
Driving through water may reduce the traction. Moisture on brakes from road water, car wash, or a coating of road salt or grit may affect braking efficiency.fCautiously apply brakes to test and dry the brakes after exposure to road water, etc.
The brake booster is ready for operation only while the engine is running. If the engine is switched off or there is a defect in the brake booster, much greater force has to be applied to the pedal when braking. fVehicles with defective brakes must not be towed and must be transported on a flat bed.
For information on towing:fPlease see the chapter “TOWING” on page 278.
Brake wear
Your car has excellent brakes, but they are still subject to wear. The rate at which they wear depends on how the brakes are used.fHave the brake system inspected at the intervals recommended in your Maintenance Booklet.
Brake system warning light
You can check the functionality of the brake system warning light by switching the ignition to the “On” position (position 1) and verifying that the warning light illuminates.
A warning message will be displayed on the multi- purpose display of the instrument panel if the brake pads are worn, excessively.fDo not continue to operate the vehicle.Have your authorized Porsche dealer inspect or replace the brake pads.
For information on warning messages on the multi-purpose display:fPlease see the chapter “OVERVIEW OF WARNING AND INFORMATION MESSAGES” on page 129.
Brake pads and brake disks
Wear on the brake pads and brake disks depends to a great extent on the driving style and the conditions of use and therefore cannot be expressed in actual miles on the road.
The high-performance brake system is designed for optimal braking effect at all speeds and temperatures.
Certain speeds, braking forces and ambient conditions (e.g. temperature and humidity) can therefore cause the brakes to “squeal”.
Unsuitable or incorrectly installed floor mats or objects can obstruct the movement of the brake pedal or prevent application of the brake pedal.fDo not obstruct the pedal travel with floor mats or other objects.
Riding the Brakes
Wet Brakes
WARNINGh
WARNINGh
Loss of Braking PowerWARNINGhBrake wear warning message USA
Brake wear warning message Canada
Obstructed Brake PedalWARNINGh
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In heavy rain, while driving through water or after leaving a car wash, the braking action may be delayed and increased pressure may be required.fFor this reason, keep further back from the vehicle in front and “dry” the brakes by applying them at intervals. Make sure that the traffic behind you is not affected.
After a long drive over salted or gritted roads, a coating may form on the brake disks and pads that significantly reduces friction and therefore also braking effect.fEven though the brake disks consist of alloyed gray cast iron, they will unavoidably start to corrode if your vehicle is parked for an extended period. The brakes will tend to “rub” as a result.The nature, extent and effects of corrosion depend on the amount of time the vehicle was parked, whether road salt or grit was spread and whether grease-dissolving agents were used in car washes (not on vehicles with Porsche Ceramic Composite Brake).To prevent corrosion of the brake disks, “brake them dry” before parking the vehicle (not on vehicles with Porsche Ceramic Composite Brake).If braking comfort is noticeably impaired, we recommend that you have the brake system checked by experts at an authorized Porsche dealer.
fTo relieve the brake system on downhill stretches, change down to a lower gear in good time (engine braking).If engine braking is insufficient on steep stretches, operate the footbrake at intervals. Avoid continuous braking as it overheats the brakes and reduces the braking effect.
For information on brake fluid and checking the brake fluid level:fPlease see the chapter “BRAKE FLUID” on page 243.
New brake pads or linings
New brake pads have to be “broken in”, and therefore only attain optimal friction when the car has covered several hundred miles or km.The slightly reduced braking ability must be compensated for by pressing the brake pedal harder. This applies whenever the brake pads and/or brake disks are replaced.
A - Switch cruise control on/off 1 - Set/increase desired speed 2 - Reduce desired speed 3 - Interrupt (OFF) 4 - Return to set speed (RESUME)
Cruise Control
Cruise control maintains any selected speed between approx. 20–150 mph (30–240 km/h) without you having to use the accelerator.Cruise control is operated using the control stalk at the bottom left of the steering wheel.Downshifts are carried out to help maintain the pre-selected speed (especially when driving downhill).
Wet Brakes
Reduced Braking Efficiency
WARNINGh
WARNINGh
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156 Driving and Driving Safety
If the current traffic situation does not allow you to drive safely at a constant speed and with sufficient distance to the vehicle in front, using the cruise control can cause accidents.fDo not use the cruise control in heavy traffic, in city traffic, on twisting roads or under unfavorable road conditions (e.g. wintry or wet conditions, varying road surfaces).fObserve all local and national speed limits.fDo not reach through the steering-wheel spokes while driving.
Switching cruise control readiness on
fPress button A on the control stalk.
Maintaining and storing speed
1.Accelerate or decelerate to the desired speed using the accelerator pedal.2. Push the control stalk on the steering wheel forward (position 1). The current driving speed is now stored as the desired speed, which will be maintained automatically.
Accelerating (e.g. to overtake)
Variant 1
fIncrease the speed as usual with the accelerator pedal.When you ease off the accelerator, the previously stored value is set again.
Variant 2
fPush the control stalk on the steering wheel forward (position 1). The desired speed is increased in steps of 1 mph (1 km/h).orPress the control stalk on the steering wheel forward and keep it pressed (position 1). The desired speed is increased in steps of 5 mph (10 km/h).
The new desired speed is displayed on the multi- function display in the instrument panel.
Decelerating
fBriefly pull the control stalk on the steering wheel towards the steering wheel (position 2). The desired speed is decreased in steps of 1 mph (1 km/h).orPull the control stalk on the steering wheel towards the steering wheel and keep it pulled (position 2). The desired speed is decreased in steps of 5 mph (10 km/h).
The new desired speed is displayed on the multi- function display in the instrument panel.
Downshifts are carried out to help maintain the pre-selected speed (especially when driving downhill).
Interrupting cruise control operation – OFF
The speed driven before the interruption remains stored in the memory and can be reactivated by pressing the control stalk.fPlease see the chapter “RESUMING THE STORED SPEED – RESUME” on page 157.fPress the control stalk down (position 3). orOperate brake pedal or move PDK selector lever to N position.
Cruise control operation is interrupted automatically:
– If the set vehicle speed is exceeded by more than approx. 16 mph (25 km/h) for longer than 20 seconds.– If Porsche Stability Management (PSM) intervenes for longer than 0.5 seconds.
Misuse of Cruise Control
Cruise control readiness
The grey symbol on the multi-function display in the instrument panel indicates readiness.
Desired speed
The desired speed that was stored is displayed under the cruise control symbol, which has now turned orange.
WARNINGh
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Resuming the stored speed – RESUME
fPress the control stalk up (position 4). Cruise control accelerates/decelerates the vehicle to the stored speed.
Information
The stored speed should only be recalled if traffic and road conditions are conducive to driving at that speed.
Switching cruise control readiness off
fPress button A on the control stalk. The memory is cleared and the readiness symbol disappears.
The stored desired speed is cleared when the ignition is switched off when the vehicle is parked.
Adaptive Cruise Control
Adaptive cruise control maintains any selected speed between approx. 20–100 mph (30–160 km/h) when driving on open roads without you having to use the accelerator.
If a vehicle traveling ahead of you in the same lane is detected as driving slower than the selected speed, adaptive cruise control will automatically maintain a set distance from the vehicle in front.Adaptive cruise control slows your vehicle down if the distance to the vehicle ahead becomes too short and accelerates your vehicle if the distance increases.
If the current traffic situation does not allow you to drive safely at a constant speed and with sufficient distance to the vehicle in front, using the adaptive cruise control can cause accidents.fDo not use the adaptive cruise control in heavy traffic, in construction traffic, in city traffic, on twisting roads or under unfavorable road conditions (e.g. wintry or wet conditions, varying road surfaces).fBrake the vehicle immediately with the footbrake if the deceleration of the adaptive cruise control is not sufficient.fMake sure that it is possible to take over control of the vehicle at all times.fObserve all local and national speed limits.
Adaptive cruise control will not detect stationary or slowly moving vehicles, pedestrians, objects on the road, oncoming vehicles in the same lane or cross traffic.fYou must pay attention to your vehicle’s position in relation to other objects and inter-vene as needed to ensure safe driving.fAlways keep the direction of travel in your field of view.
Misuse of Adaptive Cruise ControlWARNINGh
Adaptive Cruise Control Limits.WARNINGh
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Operating principle of adaptive cruise control
No vehicle detected in front – open road driving
Adaptive cruise control operates like a cruise control system. The desired speed that was set is maintained constantly.
Vehicle detected in front – driving in traffic
If a vehicle traveling ahead of you in the same lane is detected as driving slower than the selected desired speed, adaptive cruise control will automatically maintain a set distance from the vehicle in front.
If the vehicle in front stops, adaptive cruise control will slow your vehicle down to a stop provided this is possible within the control limits of the system.Adaptive cruise control actively keeps your vehicle at a standstill.
If the vehicle in front drives off, automatic speed control and distance control can be resumed.
Speed exceeded
The speed of the vehicle can be increased at any time by pressing the accelerator.
If the vehicle is traveling faster than the speed set by adaptive cruise control (ACC), adaptive cruise control is deactivated.The message “ ACC passive” appears on the multi-function display in the instrument panel.The desired speed that was stored is retained.
After releasing the accelerator pedal, the ACC accelerates to the desired speed if there is no vehicle in front and controls the distance if there is a vehicle in front.
For information on the “ ACC passive” status:fPlease see the chapter “OPERATING STATES WHEN ADAPTIVE CRUISE CONTROL IS SWITCHED ON” on page 161.R - Switch adaptive cruise control on/off 1 - Set/increase desired speed 2 - Reduce desired speed 3 - Interrupt (OFF) 4 - Operational readiness on/return to set speed (RESUME)
Using adaptive cruise control
Adaptive cruise control is operated using the control stalk at the bottom left of the steering wheel.
Information
You can intervene manually at any time by pressing the brake or accelerator.
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Examples:Switching adaptive cruise control on and off
Switching adaptive cruise control on
fPress button R on the control stalk. The grey status display appears on the multi-function display.Adaptive cruise control is ready.
Switching adaptive cruise control off
fPress button R on the control stalk. “ ACC off” appears on the multi-function display.The desired speed that was stored is deleted.The desired distance is set to the default value.
Operating states when adaptive cruise control is switched on
There are three possible operating states when adaptive cruise control is switched on.
Adaptive cruise control active
Adaptive cruise control automatically regulates the speed and distance from the vehicle in front.The status display B turns orange.
Adaptive cruise control is ready
Cruise control and distance control is inactive after pressing the brakes or interrupting by pressing the control stalk downwards (position 3, OFF ). The desired speed that was stored and the desired distance that was set are retained.The status display B turns grey.
For information on resuming cruise control and distance control:fPlease see the chapter “RESUMING CRUISE CONTROL AND DISTANCE CONTROL – RESUME” on page 164.
Adaptive cruise control passive
Cruise control and distance control is inactive after pressing the accelerator.“ ACC passive” appears on the multi-function display.The desired speed that was stored and the desired distance that was set are retained.The status display B turns grey. Adaptive cruise control is active again after you release the accelerator.
Setting and changing the desired speed
Preconditions
– Adaptive cruise control is switched on. – Vehicle is moving.– No stationary objects are detected in front.
If adaptive cruise control is switched on, and no desired speed is stored, the cruise control symbol appears but the desired speed field remains blank.
If a desired speed is stored and no vehicle was detected in front, the cruise control symbol and the desired speed are displayed.
If a desired speed is stored and a vehicle was detected in front, a vehicle symbol and the desired speed are displayed.
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Information
The distance depends on the driving speed. The slower the vehicle is traveling, the shorter the distance and the faster the vehicle is traveling, the longer the distance.
Increasing the desired distance
fPress the rocker switch Z upwards. The desired distance is increased.More orange segments are shown in the desired distance display A.
Reducing the desired distance
fPress the rocker switch Z downwards. The desired distance is reduced.Fewer orange segments are shown in the desired distance display A.
Display showing distance from vehicle in front
If a vehicle is detected in front, the vehicle symbol C appears on the multi-function display and in the status display B. The grey area D shows the current distance from the vehicle in front.
Possible distance settingsAutomatic braking to a standstill
If the vehicle in front stops, your vehicle will slow down and come to a stop within the control limits of the system if adaptive cruise control is active.The indicator light lights up on the instrument panel.The vehicle is actively held at a stop.
For information on the HOLD function:fPlease see the chapter “HOLD FUNCTION: DRIVE-OFF ASSISTANT, STANDSTILL MANAGEMENT” on page 184.
Information
– Depending on the traffic flow, e.g. slow moving traffic, stopping is initiated by a slow crawling phase, which brings the vehicle to a standstill.– When adaptive cruise control is operating normally or when the HOLD function is active, the brake pedal may feel different and you may hear hydraulic noises.This behavior is normal for the system. It is not a fault.
Suitable for speedy driving in lines of traffic. The time gap is 1 second. This corresponds to approx. 36 yd. (33 meters) at a speed of 75 mph (120 km/h).
Suitable for steady driving in lines of traffic. The time gap is 1.3 seconds. This corresponds to approx. 47 yd. (43 meters) at a speed of 75 mph (120 km/h).
Preset distance Corresponds to the general recommendation of the road traffic safety regulation (“two seconds time headway”). The time gap is 1.8 seconds. This corresponds to approx. 66 yd. (60 meters) at a speed of 75 mph (120 km/h).
Suitable for driving on country roads. The time gap is 2.3 seconds. This corresponds to approx. 63 yd. (58 meters) at a speed of 55 mph (90 km/h).
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164 Driving and Driving Safety
Driving off again
The vehicle can be driven off again after being stopped and speed and distance control will be resumed, depending on the operating state of the adaptive cruise control system.
Adaptive cruise control active
1. Press the control stalk on the steering wheel upwards (position 4, RESUME). 2. Press the accelerator pedal briefly. Your vehicle drives off again automatically.
Information
Your vehicle will not drive off if the vehicle detected in front is stationary.
Adaptive cruise control is ready
Automatic speed and distance control can only be resumed when your vehicle is moving.1. Drive off normally. 2. Press the control stalk on the steering wheel upwards (position 4, RESUME). orSet or change the desired speed.
Interrupting and resuming cruise control and distance control
Interrupting cruise control and distance control – OFF
fPress the brake pedal.orPress the control stalk on the steering wheel downwards (position 3, OFF). Adaptive cruise control is inactive.The desired speed that was stored and the desired distance are retained.
Resuming cruise control and distance control – RESUME
fPress the control stalk on the steering wheel upwards (position 4, RESUME). The vehicle accelerates to the desired speed that was stored unless a vehicle traveling in front is detected as driving slower than the desired speed and the distance from this vehicle is less than the desired distance that was set.The status display B changes from grey to orange.orPress the control stalk on the steering wheel upwards and keep it pressed (position 4, RESUME ). The vehicle accelerates in a more sporty driving style to the desired speed that was stored.
Information
If speed and distance control was interrupted by moving the control stalk to position 3 (OFF), it can only be resumed again when the vehicle is moving and no stationary objects are detected in front.
Messages on the multi-function display
If adaptive cruise control was deactivated automatically or if an action cannot be performed, a message to this effect in blue appears on the multi-function display.–“ ACC not available” Adaptive cruise control is not available, e.g. when maneuvering.–“ ACC not possible ABS/PSM intervention” Adaptive cruise control was deactivated because ABS or PSM intervened as a control mechanism.–“ Release parking brake” Adaptive cruise control was deactivated because the electric parking brake was activated.–“ ACC not possible Move gear lever to D/M ” Adaptive cruise control was deactivated because the PDK selector lever is not in position D or manual position M. –“ ACC not possible while stationary” The required action is not possible because your vehicle is stationary, e.g. when setting a desired speed.–“ ACC not possible Revs too high” Adaptive cruise control was deactivated because the engine-speed limit was reached in manual position M of the PDK selector lever/ shift paddles.–“ ACC not possible Gradient too steep” The desired distance or the desired speed cannot be set because the incline of the road is too steep.–“ ACC not possible Stationary object ahead ” The action is not possible because a stationary object was detected ahead.
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