engine VOLKSWAGEN JETTA 2017 Service Manual

Wet brakes (for example, after driving through water or washing the vehicle or after heavy rainfall) will not brake as well. Stopping distances will be longer when brake discs are wet or, in winter, even icy. Wet or icy brakes must be dried as soon as possible by carefully applying the brakes a couple of times while traveling at a relatively high speed. Make sure nobody is behind you and that you do not endan-
ger yourself or others ⇒ .
Brakes coated with road salt also react slower and need longer stopping distances. If there is salt on the roads and you are not braking regularly, brake carefully and gently from time to time to remove any
salt coating from the brake discs and pads ⇒ .
Brake disc corrosion (rust) and dirt buildup on the brake pads are more likely to occur if the vehicle is not driven much or is driven only for short distances with little braking. If the brakes have not been used and there is some rust on the discs, clean the brake discs and pads once in a while by carefully braking a couple of times while driving at relatively high speed to help clean the brake discs and pads.
Make sure nobody is behind you and that you do not endanger yourself or others ⇒ .
Brake system malfunction
If you brake and find that the vehicle doesn't brake nearly as well as it used to (sudden increase in stopping distance), a brake circuit may have failed. The brake warning light H or "2!+% will light up and a message may appear in the instrument cluster display. If you believe the vehicle is safe to drive, immediately take it to the nearest authorized Volkswagen dealer or authorized Volkswagen Service Facility for repair. Drive slowly and very carefully, allow for the longer stopping distance, and be ready to push longer and harder on the brake pedal to slow the vehicle down.
Brake booster
The brake booster works only when the engine is running. It increases the force on the brakes above and beyond the pressure put on the brake pedal by the driver.
If the brake booster is not working, or if the vehicle has to be towed, you will have to push the brake pedal harder to make up for the lack of booster assistance and the resulting longer stopping distance
⇒ .
WARNING
New brake pads do not provide maximum braking performance.
x New brake pads do not have the best stopping power for the first 185 miles (300 km) and must be “broken in.” You can compensate for the slightly reduced braking force by putting more pressure on the brake pedal.
x Drive with extra care while the new brake pads are being broken in. This reduces the risk of collisions and serious personal injuries due to a loss of control over the vehicle.
x Never follow other vehicles too closely or put yourself into other situations that might require sudden, hard braking, especially when the brake pads have not been broken in.
WARNING
Overheated brakes will reduce the vehicle's stopping power and increase stopping distances considerably.
x When driving downhill, the brakes have to work especially hard and heat up quickly.
x Before driving downhill, especially on hills that are long or steep, always reduce speed and shift into lower gear (manual or automatic transmission). This will let the vehicle use engine braking and reduce the load on the brakes. Otherwise, the brake system could over-heat and possibly fail. Only use the brakes when you need them to slow the vehicle down more or to stop.
x A damaged front bumper or a non-standard spoiler can reduce airflow to the brakes and make them overheat.

WARNING
Wet brakes or brakes coated with ice or road salt react slower and need longer stopping dis-tances.
x Carefully apply the brakes to test them.
x Always dry brakes and clean off ice and salt coatings with a few cautious brake applica-tions when visibility, weather, road and traffic conditions permit.
WARNING
Driving when the brake booster is not working increases stopping distances and can cause accidents and serious personal injuries.
x Never let the vehicle coast when the engine is switched off.
x If the brake booster is not working (such as when the vehicle is being towed), a lot more pedal force is needed to slow down and stop.
NOTICE
x Never “ride” the brakes by keeping your foot on the brake pedal when you do not want to brake. Constant pressure on the brake pedal can make the brakes overheat. Riding the brakes will substantially reduce braking performance, increase stopping distance, and can cause complete brake system failure.
x Before driving downhill, especially on hills that are long or steep, always reduce speed and shift into lower gear (manual or automatic transmission). This will let the vehicle use engine braking and reduce the load on the brakes. Otherwise, the brake system could overheat and possibly fail. Only use the brakes when you need them to slow the vehicle down more or to stop.
When the front brakes are serviced, you should have the rear brake pads inspected at the same time. The wear of all brake pads should be visually checked regularly. The best way to check for brake pad wear is to have your authorized Volkswagen dealer or authorized Volkswagen Service Facility visually inspect the pads through the openings in the wheel rims or from underneath the vehicle. If necessary, the wheels can be taken off for a more thorough inspection.
Braking assistance systems

not always be able to help you master situations where there is a sudden change in the coefficient of friction of the road surface. When there is a section of dry road that is suddenly covered with water, slush or snow, ESC cannot perform the same way it would on a dry surface. If the vehicle “hydro-planes” (rides on a cushion of water instead of the road surface), ESC will not be able to help you steer the vehicle because contact with the pavement has been interrupted and the vehicle cannot be braked or steered. During fast cornering, particularly on winding roads, ESC cannot always deal as effectively with difficult driving situations as it can at lower speeds. When towing a trailer, ESC is not able to help you regain control as it would if you were not towing a trailer.
Always adjust your speed and driving style to visibility, road, traffic, and weather conditions. ESC cannot override the vehicle's physical limits, increase the available traction, or keep a vehicle on the road if road departure is a result of driver inattention. Instead, ESC improves the possibility of keeping the vehicle under control and on the road during extreme maneuvers by using the driver's steering inputs to help keep the vehicle going in the intended direction. If you are traveling at a speed that causes you to run off the road before ESC can provide any assistance, you may not experience the benefits of ESC.
ESC includes and/or works together with the ABS, BAS, ASR, EDL, and XDL systems (see below). ESC is switched on all the time and cannot be switched off.
Anti-Lock Brake System (ABS)
ABS helps to keep the wheels from locking up and helps to maintain the driver's ability to steer and control the vehicle. This means the vehicle is less likely to skid, even during hard braking:
x Push the brake pedal down hard and hold it there. Don't take your foot off the pedal or reduce the force on the pedal!
x Do not “pump” the brake pedal or let up on it!
x Steer the vehicle while pushing down hard on the brake pedal.
x ABS stops working if you release or let up on the brake.
When ABS is doing its job, you will notice a slight vibration through the brake pedal and hear a noise. ABS cannot shorten the stopping distance under all conditions. The stopping distance may even be longer, for instance, when driving on gravel or on newly fallen snow covering an icy or slip-pery surface.
Brake Assist (BAS)
The Brake Assist System can help to reduce stopping distances. If you press the brake pedal very quickly, BAS detects an emergency situation. It then very quickly builds up full brake system pressure, maximizing braking power and reducing the stopping distance. This way, ABS can be activated more quickly and efficiently.
Do not reduce pressure on the brake pedal! BAS switches off automatically as soon as you release or let up on the brake.
Anti-Slip Regulation (ASR)
ASR reduces engine power directed to spinning wheels and adjusts power to the road conditions. Even under poor road conditions, ASR can make it easier to get moving, accelerate, and climb hills.
ESC and ASR can help when driving on loose surfaces (such as gravel) and in deep snow. If you get stuck in deep snow, you may be able to get going again by “rocking” the vehicle back and forth. ESC and ASR recognize this special driving situation and automatically increase the speed of the front wheels. Keep pressing the accelerator and let ESC increase the speed of the front wheels to help you keep moving or get moving again.
Electronic Differential Lock (EDL and XDL)
EDL is applied during regular straight-line acceleration. EDL gently brakes a drive wheel that has lost traction (spinning) and redirects the drive force to other drive wheels. In extreme cases, EDL automat-ically switches off to keep the brake from overheating. As soon as the brake has cooled down, EDL automatically switches on again.

XDL is an extension of the Electronic Differential Lock system. XDL does not react to drive wheel slippage when driving straight ahead. Instead, XDL detects slippage of the inside front wheel during fast cornering. XDL applies enough brake pressure to this wheel in order to stop the slippage. This improves traction, which helps the vehicle stay on track.
WARNING
Driving fast on icy, slippery, or wet roads can lead to a loss of control and result in serious personal injury for you and your passengers.
x Always adjust your speed and driving style to road, traffic, weather, and visibility condi-tions. Never let the additional safety that ESC, ABS, BAS, ASR, and EDL can provide tempt you into taking extra risks.
x Braking assistance systems cannot overcome the laws of physics and always prevent loss of vehicle control. Slippery and wet roads are still dangerous even with ESC and the other systems!
x Driving too fast on wet roads can cause the wheels to lose contact with the road and “hy-droplane.” A vehicle that has lost road contact cannot be braked, steered, or controlled.
x These systems cannot reduce the risk of accident, for example if you drive too fast for conditions or if you do not keep your distance from the vehicle in front of you.
x Although these systems are very effective and can help you control the vehicle in many difficult situations, always remember that your vehicle handling control is limited by tire trac-tion.
x When accelerating on a slippery surface, for example on ice and snow, depress the accel-erator carefully. Even with these systems, the wheels may start to spin, leading to a loss of vehicle control.
WARNING
The effectiveness of ESC can be significantly reduced if other components and systems that affect vehicle dynamics, including but not limited to brakes, tires, and other systems men-tioned above, are not properly maintained or functioning.
x Always remember that vehicle alterations or modifications can affect the functioning of the ABS, BAS, ASR, EDL, and ESC systems.
x Changing the vehicle suspension or using an unapproved tire/wheel combination can change the way the ABS, BAS, ASR, EDL, and ESC systems work and reduce their effective-ness.
x The effectiveness of ESC is also determined by the tires fitted ⇒  Tires and wheels.
All 4 wheels must be equipped with identical tires in order for ESC and ASR to work properly. Differences in the tread circumference of the tires can cause the system to reduce the engine power when it is not expected.
If ABS is not working, ESC, ASR, and EDL will also not work.
You may hear noises when these systems are active.

Brake fluid

Fig. 134 In the engine compartment: Brake fluid reservoir cap.

speed fluctuations caused by taking your foot off the accelerator. Active braking and accelerating is then not necessarily required.
Calm and smooth driving
Consistency is more important than speed. The more smoothly you drive, the less fuel the vehicle consumes.
When driving on the highway or freeway, a constant, moderate speed is more efficient and economical than constantly accelerating and braking. Usually you can reach your destination just as quickly by driving at a moderate, but steady speed.
The cruise control can assist in maintaining a uniform driving style.
Moderate use of extra electrical loads
Comfort inside the vehicle is nice and important, but it is important to use them in an environmentally conscious manner.
Some devices can increase fuel consumption when activated (examples):
x Climate control system (air conditioner): If the air conditioner has to produce starkly contrasting temperatures, it requires a large amount of energy, which is generated by the engine. The temperature in the vehicle should therefore not be extremely different from that of the outside temperature. It may be helpful to ventilate the vehicle before driving and then to drive a short distance with the windows open. After that, switch on the air conditioner with the windows closed. Keep the windows closed when driving at high speeds. Open windows increase fuel consumption.
x Switch off seat heating once it has served its purpose.
x Switch off the rear window defroster as soon as the windows are free of fog and ice.
Additional factors that increase fuel consumption (examples):
x Malfunctioning engine control.
x Driving in the mountains.
x Towing a trailer.
NOTICE
Never let the vehicle coast or roll down a hill in Neutral (N), especially when the engine is not running. The transmission will not be lubricated and will be damaged.

Adjust the tire pressure
The proper tire pressure helps reduce rolling resistance as well as fuel consumption.
When purchasing new tires, always make sure that the tires are optimized for lower rolling resistance.
Use low viscosity engine oil
Fully “synthetic,” low viscosity engine oils that expressly comply with Volkswagen oil quality standards reduce fuel consumption. Low viscosity engine oils reduce the frictional resistance on the engine and are distributed more evenly and quickly, particularly when cold-starting the engine. The effect is partic-ularly apparent in vehicles that frequently travel short distances.
Always ensure the right engine oil level is maintained and keep to the scheduled service intervals (engine oil changes).
Make sure the engine oil that you purchase expressly complies with Volkswagen oil quality standards and is the oil approved by Volkswagen for your vehicle.
Avoid unnecessary weight
The lighter the vehicle, the more economical and eco-friendly it will be. For example, an extra 220 lbs (100 kg) of weight increases fuel consumption by up to 1 pint per 60 miles (0.3 l/100 km).
Remove all unnecessary items and unnecessary dead weight from the vehicle.
Remove unnecessary aftermarket components
The more aerodynamic the vehicle, the less fuel it will consume. Aftermarket components such as bicycle racks reduce its aerodynamic performance.
Therefore, remove unnecessary structures and unused rack systems, particularly if planning to drive at higher speeds.

and release the parking brake while depressing the accelerator. For Hill Hold to work, the engine must be running and the vehicle must be in First Gear or Reverse (manual transmission) or in Drive (D), Sport Drive (S), or Reverse (R) (automatic transmission) and you must use the foot brake to hold the vehicle before starting to move.
Hill Hold keeps the brake applied for not quite 2 seconds with the same force you used to prevent the vehicle from moving. This gives you time to take your foot off the brake, let the clutch out on a manual transmission vehicle, and gently depress the accelerator to get the vehicle moving again. If you do not depress the accelerator pedal and get the vehicle moving again within this time, the brakes will release and the vehicle will roll downhill. Furthermore, if any requirement for engaging Hill Hold is no longer met while the vehicle is stopped, Hill Hold disengages and the brakes are automatically released and will no longer hold the vehicle.
Hill Hold is activated automatically when points 1 to 3 are met at the same time:

Step Manual transmission Automatic transmission
1. Hold the stopped vehicle on an incline with the foot or parking brake.
2. The engine must be running “smoothly.”
3.
A manual transmission vehicle must be in 1st gear (1) if headed up a hill or in Reverse (R) if backing up a hill; you must hold the clutch down and the foot brake must be depressed to keep the vehicle from moving.
An automatic transmission vehicle must be in Reverse (R), Drive (D), or Sport Drive (S) and the foot brake must be depressed to keep the vehicle from moving.
4.
To drive off, take your foot off the brake pedal as you let the clutch out and gently depress the accelerator within 2 seconds. If the accel-erator is not depressed, the brakes will re-lease automatically.
To drive off, take your foot off the brake pedal and gently depress the accelerator within 2 seconds.

Hill Hold is immediately deactivated:
x If any requirement listed in the table above is no longer met.
x If the engine is not running smoothly or the engine malfunctions.
x If the engine stalls or is switched off.
x If the driver door is opened.
x Automatic transmission vehicles: If the transmission is in Neutral (N).
x Automatic transmission vehicles: If a tire does not have enough road contact (such as when the vehicle is tipped or at an angle).
WARNING
The intelligent technology of Hill Hold cannot overcome the laws of physics. Never let the increased convenience provided by Hill Hold tempt you into taking risks.
x The Hill Hold feature cannot hold the vehicle in all hill start situations (for example, if the surface is icy or slippery).
x Hill Hold can only help keep the vehicle from moving for less than 2 seconds. After that, the brakes will be released and the vehicle can roll down the hill.

WARNING
Poor visibility increases the risk of collisions and other accidents that cause serious person-al injuries.
x Always make sure all windows are clear of ice, snow and condensation for good visibility to the front, sides, and rear.
x Maximum heating output and defrosting performance are not possible until the engine has reached operating temperature. Wait until you have good visibility before driving off.
x Always make sure you know how to properly use the climate control system as well as the rear window defroster that you will need for good visibility.
x Never use air recirculation for long periods of time. When the air conditioner is off and recirculation mode is on, condensation can quickly form on the windows and greatly reduce visibility.
x Always switch off recirculation mode when it is not needed.
WARNING
Stale air causes driver fatigue and reduces driver alertness, which can cause accidents, colli-sions and serious personal injury.
x Never switch off the fan for a long period of time and never use air recirculation for a long period of time because no fresh air will enter the passenger compartment.
NOTICE
x If you think the air conditioner is not working properly or may be damaged, switch it off to help prevent more damage. Have the air conditioner checked by an authorized Volkswagen dealer or an authorized Volkswagen Service Facility.
x Air conditioner repair requires specialized knowledge and special tools. Volkswagen rec-ommends that you see an authorized Volkswagen dealer or an authorized Volkswagen Service Facility.
x Do not smoke when air recirculation is switched on. Smoke drawn into the ventilation sys-tem can leave residue on the evaporator and on the dust and pollen active carbon filter, result-ing in permanent odors whenever the air conditioner is switched on.
If the air conditioner is switched off, the fresh outside air will not be dehumidified. To help keep the windows from fogging over, Volkswagen recommends leaving the air conditioner (compressor) switched on. Press the !

Emergency starting and starting the engine with a very weak vehicle battery or after the vehicle battery has been replaced may change or delete system settings (including time, date, personal con-venience settings, and programming). Check the settings and correct as necessary once the vehicle battery has built up a sufficient charge.
Manual controls

Fig. 151 In the center console: Manual air conditioning controls.