service VOLKSWAGEN JETTA 2018 Service Manual

WARNING
Failure to heed warning lights and instrument cluster text messages can cause the vehicle to break down in traffic and result in a collision and serious personal injury.
x Never ignore warning lights or text WARNINGS.
x Always stop the vehicle as soon as it is safe to do so.
WARNING
Driving with bad brakes can cause a collision and serious personal injury.
x If the brake warning light "2!+% or H does not go out, or lights up when driving, either the brake fluid level in the reservoir is too low or there is a fault in the brake system. Stop the
vehicle as soon as you can do so safely and get expert assistance ⇒ page 242, Brake fluid.
x If the brake warning light "2!+% or H lights up at the same time as the ABS warning light !"3 or J, the ABS may not be working properly. This could cause the rear wheels to lock up rela-tively quickly during braking. Rear wheel brake lock-up can cause loss of vehicle control.
x If you believe the vehicle is safe to drive, drive slowly and very carefully to the nearest authorized Volkswagen dealer, authorized Volkswagen Service Facility, or other qualified workshop and have the brake system inspected. Avoid sudden hard braking and steering.
x If the ABS indicator light !"3 or J does not go out, or if it lights up while driving, the ABS system is not working properly. The vehicle can then be stopped only with the standard brakes (without ABS). You will not have the protection ABS provides. Contact your author-ized Volkswagen dealer or an authorized Volkswagen Service Facility as soon as possible.
x If the brake pads are worn or you notice changes in the way the vehicle brakes, immedi-ately contact an authorized Volkswagen dealer or authorized Volkswagen Service Facility to have the brake pads checked and, if necessary, replaced.
NOTICE
Failure to heed warning lights or text WARNINGS can result in vehicle damage.
Parking brake

Fig. 133 Between the front seats: Parking brake.

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

Changing brake fluid
Brake fluid must be changed according to the service schedule in your ⇒ Booklet Warranty and
Maintenance. Have the brake fluid checked by an authorized Volkswagen dealer or an authorized Volkswagen Service Facility. Refill only with new brake fluid that meets the standards listed above.
WARNING
Brake failure and reduced brake performance can be caused by not having enough brake fluid in the reservoir or by old or incorrect brake fluid.
x Check the brake system and brake fluid level regularly.
x Always change the brake fluid according to the service schedule in your
⇒ Booklet Warranty and Maintenance.
x Hard braking with old brake fluid may cause vapor lock. Vapor lock reduces braking per-formance, increases stopping distances and can even cause total brake failure.
x Always make sure that only the correct brake fluid is used. Only use brake fluid that ex-pressly conforms to VW Standard 501 14 or, if it is not available, only use a high-quality brake fluid that conforms to U.S. Standard FMVSS 116 DOT 4 requirements.
x Using another brake fluid, or one that is not of high quality, can impair the function of the brake system and reduce its effectiveness. If the container does not say that the brake fluid complies with VW Standard 501 14, or U.S. Standard FMVSS 116 DOT 4, do not use it.
x The brake fluid must be new.
WARNING
Brake fluid is poisonous.
x To reduce the risk of poisoning, never use food, beverage or other non-original containers to store brake fluid. Someone might be misled by the original label on the container, or by the shape of the container, and drink the brake fluid. This could occur even if you relabel the container as “brake fluid.”
x Only store brake fluid in the closed, original container and keep it out of the reach of chil-dren.
NOTICE
Brake fluid will damage vehicle paint, plastic parts, and tires. Wipe any brake fluid off vehicle paint and other vehicle parts immediately.
Brake fluid can pollute the environment. Brake fluid that has leaked out must be collected and disposed of properly, following all applicable environmental regulations.

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.

Display
Different cruise control versions are available. The stored speed is shown in the instrument cluster display on some equipment versions.
Status fig. 137
(A) Cruise control temporarily deactivated. Stored speed displayed in small numbers.
(B) System malfunction. See an authorized Volkswagen dealer or an authorized Volkswagen Service Facility.
(C) Cruise control activated. No speed stored in memory.
(D) Cruise control is active. Stored speed displayed in large numbers.
Indicator lights

Lights up Possible cause
% Cruise control is regulating the vehicle speed. #25)3%

When the ignition is switched on, several warning and indicator lights come on briefly for a function check. They go out after a few seconds.
WARNING
Failure to heed warning lights and instrument cluster text messages can cause the vehicle to break down in traffic and result in a collision and serious personal injury.
x Never ignore warning lights or text WARNINGS.
x Always stop the vehicle as soon as it is safe to do so.
NOTICE
Failure to heed warning lights or text WARNINGS can result in vehicle damage.
Cruise control operation

Fig. 138 Left-hand side of the multi-function steering wheel: Buttons for operating the cruise control .

NOTICE
x The radar sensors in the rear bumper can be damaged or become misaligned in low-speed impacts and parking maneuvers. The system can switch itself off or may be impaired as a result.
x Always keep the rear bumper clean and free of snow and ice so that the radar sensors can function properly. Do not cover the radar sensor area.
x The rear bumper may only be painted with vehicle paint that is approved by Volkswagen. Other paints may impair the function of the Blind Spot Monitor or cause it to malfunction.
x Sunlight may reduce the visibility of the indicator light in the outside mirror.
If the system does not function as described in this chapter or if your vehicle was involved in a collision, do not use the Blind Spot Monitor with Rear Traffic Alert. See an authorized Volkswagen dealer or an authorized Volkswagen Service Facility to have the system checked.
Indicator lights

WARNING
The Forward Collision Warning system technology cannot overcome the laws of physics and system-related limits. The driver is always responsible for braking in time. If the Forward Collision Warning system issues a warning, immediately apply the brake to slow the vehicle down or avoid the obstacle, depending on the traffic situation.
x Always adjust your speed and driving style to road, traffic, weather, and visibility condi-tions.
x The Forward Collision Warning system cannot prevent accidents and serious injuries on its own.
x The Forward Collision Warning system can issue unnecessary warnings in certain com-plex driving situations, for example, at traffic islands.
x The Forward Collision Warning system can issue unnecessary warnings when its function is impaired, for example, if the radar sensor is dirty or if the position of the radar sensor has been changed.
x The Forward Collision Warning system does not react to people, animals, or vehicles crossing or approaching in the same lane.
x Always be prepared to take full control of the vehicle at all times.
Deactivate the Forward Collision Warning system if it does not work as described in this chapter, for example, if multiple unwanted warnings occur. Have the system checked by an authorized Volkswagen dealer or authorized Volkswagen Service Facility.
Displays

Fig. 147 In the instrument cluster display: Distance warning.

should only be carried out by a qualified workshop ⇒  Parts, accessories, repairs, and modifications. Contact an authorized Volkswagen dealer or an authorized Volkswagen Service Facility for assis-tance.
Incorrectly performed repairs to the front end of the vehicle can change the position of the radar sen-sor and therefore impair the function of the Forward Collision Warning system. Repair work should only be carried out by a qualified workshop. Contact an authorized Volkswagen dealer or an author-ized Volkswagen Service Facility for assistance.
NOTICE
Switch off the Forward Collision Warning system if you suspect that the radar sensor has been damaged or if its position has been changed. This can help prevent further damage. Contact an authorized Volkswagen dealer or an authorized Volkswagen Service Facility to have the radar sensor realigned.
x The radar sensor can become misaligned if it is hit, for example, when parking the vehicle. Readjusting the sensor could impair the performance of the system or cause it to switch off.
x Repairs to the radar sensor require special knowledge and tools. Contact an authorized Volkswagen dealer or an authorized Volkswagen Service Facility for assistance.
x Remove snow with a brush, and remove ice with a solvent-free deicer spray.
Operating the Forward Collision Warning system (Front Assist)

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 !