Get Checking and filling -> 12 V vehicle battery Guide for Volkswagen Jetta 4 Door Seventh Generation (2019-2025)

WARNING

A low brake ﬂuid level or unsuitable brake ﬂuid may cause the brakes to fail or may reduce braking efﬁciency. Accidents

and serious or fatal injuries could result.

Have the brake system and brake ﬂuid level checked regularly.

Be sure to use the correct brake ﬂuid.

Only use brake ﬂuid that expressly complies with the VW standard 501 14.

Only use a high-quality brake ﬂuid that complies with DIN ISO 4925 CLASS 6 or the US standard

FMVSS 116 DOT 4 in the exceptional case that a brake ﬂuid that conforms to VW standard 501 14 is not available.

Changing brake ﬂuid

An authorized Volkswagen dealer or authorized Volkswagen Service Facility can provide information about the interval for

changing the vehicle brake ﬂuid. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized

Volkswagen Service Facility.

Have the brake ﬂuid changed regularly.

Only have brake ﬂuid added that meets the required speciﬁcations.

WARNING

Vapor lock may occur in old brake ﬂuid due to absorbed moisture during hard braking, reducing braking efﬁciency and

potentially causing total brake failure. Accidents and serious or fatal injuries could result.

Have the brake ﬂuid changed regularly.

Only have new brake ﬂuid added.

Troubleshooting

Please read the introductory information and heed the Warnings and Notice ⇒

hood space.

Safety precautions for working in the

Brake ﬂuid level

The red warning light turns on. The brake ﬂuid level is too low.

Do not continue driving! This could result in the brake failing.

1. Stop the vehicle immediately as soon as it is safe to do so ⇒ Parking.

2. Check the brake ﬂuid level.

3. If the brake ﬂuid level is too low, contact an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

12 V vehicle battery

Introduction

The 12-volt vehicle battery is a component of the electrical system and serves to supply energy to the vehicle. During

maintenance procedures, the 12 V vehicle battery is checked and replaced if necessary.

You may only perform procedures on the electrical system yourself if you are familiar with the necessary activities and the

general safety precautions, and if the correct operating equipment and ﬂuids and suitable tools are available. Work performed

incorrectly can result in serious injuries ⇒

.

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Information about warning and indicator lights can be found in the troubleshooting section at the end of the chapter

⇒ Troubleshooting.

Battery switch-off in an accident with triggering of the airbag

In vehicles with a 12 V vehicle battery in their vehicle interior or luggage compartment, the electrical connection to the 12 V

vehicle battery is pyrotechnically disconnected in an accident with airbag deployment. This prevents a short circuit. For more

information on the installation location of the vehicle battery, refer to section → page , Checking the 12 V vehicle battery acid

level.

Detailed warnings for the 12 V vehicle battery

Always wear eye protection.

Battery acid is highly corrosive. Always wear protective gloves and eye protection.

Fire, sparks, open flame, and smoking are forbidden. A highly explosive mixture of gases forms when charging the 12 V

vehicle battery. Always keep children away from battery acid and the 12 V vehicle battery.

Manual.

Always heed the Owner's

WARNING

Performing work on the 12 V vehicle battery and the electrical system can cause serious injuries, ﬁres, or electric shocks.

This could result in serious injuries.

Always read and follow the warning information on the 12 V vehicle battery.

Before performing any work on the 12 V vehicle battery, switch off the ignition and all electrical equipment and

disconnect the 12 V battery negative cable.

Always keep children away from battery electrolyte and the 12 V vehicle battery.

When handling 12 V vehicle batteries, always protect your hands, arms, and face from spraying battery acid.

Always wear eye protection and safety gloves.

Never short circuit the battery terminals.

Have all work performed by suitably qualiﬁed professionals. Volkswagen recommends contacting an authorized

Volkswagen dealer or authorized Volkswagen Service Facility.

WARNING

When work is carried out on the 12 V vehicle battery, a highly explosive, ﬂammable gas mixture builds up. Sparks could

form and ignite the ﬂammable gas that is released by the 12 V vehicle battery. This can result in serious injury or death.

Always keep ﬁres, sparks, open ﬂames, and lit cigarettes far away from the 12 V vehicle battery.

Avoid creating sparks when working with wires and electrical equipment or when discharging static electricity.

WARNING

California Proposition 65 Warning.

This product can expose you to chemicals including lead and lead components, which are known to the State of

California to cause cancer and birth defects or other reproductive harm. For more information go to

https://www.P65Warnings.ca.gov.

NOTICE

UV rays can damage the battery housing.

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Do not expose the 12 V vehicle battery to direct sunlight for a long period of time.

NOTICE

The 12 V vehicle battery could freeze and be destroyed.

Protect the 12 V vehicle battery against freezing temperatures if the vehicle is parked for long periods of time.

System settings after a battery change

If the 12 V vehicle battery is replaced or after a successful jump-start, system settings may be changed or deleted.

1. Check the date and time and adjust them if necessary.

2. Check personal convenience settings and adjust and save them as necessary.

12 V vehicle batteries can contain toxic substances such as sulfuric acid and lead. Dispose of the 12 V vehicle battery

according to legal and environmental regulations and only at a collection point for old batteries, e.g. a recycling center or

specialist retailer.

Battery acid can pollute the environment. Collect any leaking ﬂuids and dispose of them according to legal and

environmental regulations.

Checking the 12 V vehicle battery acid level

Please read the introductory information and heed the Warnings and Notice ⇒

hood space.

The 12 V vehicle battery does not require any maintenance.

Safety precautions for working in the

Check the acid level of the 12 V vehicle battery regularly if mileage is high, in countries with warm climates, or if the 12 V

vehicle battery is old. Otherwise, the 12 V vehicle battery is maintenance-free.

12 V vehicle battery location

The 12 V vehicle battery is located in the hood space.

Preparations

1. Prepare the vehicle for work in the hood space.

2. Wear suitable eye protection and safety gloves.

3. Open the hood.

Checking the Acid Level

WARNING

Battery acid is corrosive. Contact with battery acid, especially swallowing battery acid, can result in serious burns.

Never open a 12 V vehicle battery.

Never tilt the 12 V vehicle battery. Acid can leak out of the vent openings.

Protect your skin, face, and particularly your eyes when working with the 12 V vehicle battery.

Do not eat, drink, or smoke when working on the 12 V vehicle battery.

Wash your skin with soap and water after working on the 12 V vehicle battery.

If acid comes into contact with your skin or hair, remove all soiled or wet clothing and wash your skin and hair with

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water. Consult a doctor.

If acid comes into contact with your eyes, rinse the affected area carefully with water for several minutes. Then

consult a doctor immediately.

If you swallow battery acid, immediately drink plenty of water and swallow activated charcoal. Consult a doctor

immediately.

If you have inhaled acid vapors, leave the hazard area and breathe in fresh air. Consult a doctor immediately.

WARNING

When work is carried out on the 12 V vehicle battery, a highly explosive, ﬂammable gas mixture builds up. Sparks could

form and ignite the ﬂammable gas that is released by the 12 V vehicle battery. This can result in serious injury or death.

Always keep ﬁres, sparks, open ﬂames, and lit cigarettes far away from the 12 V vehicle battery.

Avoid creating sparks when working with wires and electrical equipment or when discharging static electricity.

Depending on the vehicle equipment, an additional bracket must be removed to see the viewing window. An additional tool

that is not available in the vehicle tool kit is required to do this. Always have the acid level of the 12 V vehicle battery checked

by an authorized Volkswagen dealer or authorized Volkswagen Service Facility. Volkswagen recommends contacting an

authorized Volkswagen dealer or authorized Volkswagen Service Facility.

Fig. 172 On the top of the 12 V vehicle battery: Window (general example).

Make sure there is enough lighting to clearly see the color indicator in the circular window on the top of the 12 V vehicle batter

ﬁg. 172.

Light yellow or colorless

The 12 V vehicle battery acid level is too low. Have the 12 V vehicle battery replaced by an authorized Volkswagen

dealer or authorized Volkswagen Service Facility. Volkswagen recommends contacting an authorized Volkswagen dealer

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or authorized Volkswagen Service Facility.

Black

The 12 V vehicle battery acid level is OK.

The acid level of 12 V vehicle batteries labeled AGM cannot be checked for technical reasons. Suitably qualiﬁed professiona

can inspect the battery. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen

Service Facility.

Charging, replacing, disconnecting, or connecting the 12 V vehicle battery

Please read the introductory information and heed the Warnings and Notice ⇒

hood space.

Safety precautions for working in the

If you suspect that the 12 V vehicle battery is damaged or malfunctioning, see suitably qualiﬁed professionals to have the 12 V

vehicle battery checked. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen

Service Facility.

Charging the 12 V vehicle battery

The 12 V vehicle battery should be charged by suitably qualiﬁed professionals because the 12 V vehicle battery that is

installed at the factory requires a charging process where the voltage is limited ⇒

. Volkswagen recommends contacting

an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

Replacing the 12 V vehicle battery

The 12 V vehicle battery is designed to ﬁt the location where it is installed and is equipped with safety features. If a 12 V

vehicle battery needs to be replaced, have the replacement part ﬁtted by qualiﬁed professionals. Check with qualiﬁed

professionals to ﬁnd out the component information regarding size and the required maintenance, performance, and safety

features. They must possess the necessary technical documentation and equipment. Volkswagen recommends contacting an

authorized Volkswagen dealer or authorized Volkswagen Service Facility. The vent opening on the 12 V vehicle battery must

always be located on the negative terminal side. The vent opening on the positive terminal side must always be sealed ⇒

Only use a maintenance-free 12 V vehicle battery that conforms to the TL 825 06 and VW 7 50 73 standards. These

standards must be from October 2014 or later.

Always have the 12 V vehicle battery replaced by qualiﬁed professionals because the vehicle electronics must be adapted as

part of the replacement. Only qualiﬁed professionals have the necessary equipment to perform the adaptation and have

access to the correct replacement batteries.

Disconnecting the 12 V vehicle battery

If the 12 V vehicle battery must be disconnected from the vehicle electrical system, note the following:

1. Switch off all electrical consumers.

2. Unlock the vehicle before disconnecting the battery. Otherwise, the anti-theft alarm system will be triggered.

3. Disconnect the negative cable ﬁrst, and then the positive cable ⇒

.

Connecting the 12 V vehicle battery

If the 12 V vehicle battery must be connected to the vehicle electrical system, note the following:

1. Switch off all electrical consumers.

2. Connect the positive cable ﬁrst, and then the negative cable ⇒

.

Various indicator lights may turn on after connecting the 12 V vehicle battery and switching the ignition on. They will turn off

after driving a short distance at a speed of approx. 15 to 20 km/h (approx. 10 to 12 mph). If the indicator lights light up and

remain on, contact an authorized Volkswagen dealer or authorized Volkswagen Service Facility and have the vehicle

checked. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

If the 12 V vehicle battery was disconnected for a long period of time, the next scheduled maintenance may not display

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correctly or it may not be calculated correctly ⇒ Service interval display. Follow the maximum permissible service intervals

⇒ Maintenance.

Vehicles with a starter button: If the ignition cannot be switched on after connecting the 12 V vehicle battery, carry out the

following activities:

1. Lock and unlock the vehicle from the outside.

2. Try to switch the ignition on again.

3. If the ignition will not switch on, see an authorized Volkswagen dealer or authorized Volkswagen Service Facility for

assistance.

Automatic equipment deactivation

If the ignition is switched on for a very long time when the engine is off or the parking light is switched on when parking for a

very long time, the intelligent power management cannot always prevent the 12 V vehicle battery from being drained.

If the 12 V vehicle battery is under a heavy load, the intelligent power management will automatically begin certain measures

to prevent the 12 V vehicle battery from draining.

The idle speed will be increased so that the alternator delivers more power.

If necessary, equipment that uses a lot of power will have its performance limited or will be switched off.

The power supply to the 12 V socket will be interrupted temporarily when the engine is started.

12 V Vehicle Battery Draining

If the battery is drained, it may not be possible to start the engine. The 12 V vehicle battery will be drained in the following

situations:

If the vehicle is parked for long periods of time without running the engine, especially if the ignition is on.

If electrical equipment is used when the ignition is switched off.

WARNING

Use of a 12 V vehicle battery that does not have identical speciﬁcations and dimensions to the 12 V vehicle battery that

was installed at the factory may cause short circuits or ﬁre. This could result in serious or fatal injuries.

Always use a maintenance-free and leak-proof 12 V vehicle battery that has the same characteristics,

speciﬁcations, and dimensions as the 12 V vehicle battery that was installed at the factory.

WARNING

Fitting 12 V vehicle batteries incorrectly may cause short circuits or ﬁre. This could result in serious or fatal injuries.

Always attach the 12 V vehicle battery to the attachment points provided in the vehicle.

Replace all covers that are required for the vehicle back on the battery.

WARNING

A highly explosive mixture of oxyhydrogen can form when charging the 12 V vehicle battery. Sparks or naked ﬂames

could ignite the gas mixture. This could cause serious burns.

Only charge 12 V vehicle batteries in well-ventilated areas.

Keep sparks and naked ﬂames away from the 12 V vehicle battery.

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WARNING

If the degassing tube is not attached to the 12 V vehicle battery correctly, the highly explosive gas mixture that builds up

when the vehicle is running may enter the vehicle interior. The ﬂammable gas could ignite and cause serious injuries or

death.

For vehicles with the 12 V vehicle battery in the vehicle interior or luggage compartment, ensure that the degassing

hose is connected to the 12 V vehicle battery correctly. The degassing hose must always be connected to the

negative terminal side of the 12-volt vehicle battery.

Always ensure that the opening on the positive terminal side of the 12 V vehicle battery is capped.

CAUTION

A drained 12 V vehicle battery can freeze at temperatures around 0 °C (+32 °F). Acid can escape from a frozen and

defrosted 12 V vehicle battery. This can cause injuries and long-term damage to the vehicle.

Never charge a frozen or thawed 12 V vehicle battery.

Always replace the 12 V vehicle battery if it freezes.

CAUTION

Cables that are connected incorrectly can cause a short circuit. This could damage the on-board electronics and result in

serious injuries.

Connect the positive cable ﬁrst and then the negative cable.

NOTICE

If the 12 V vehicle battery is connected or disconnected when the ignition is switched on or the engine is running, this

could damage the electrical system or electronic components, resulting in electrical malfunctions.

Never connect or disconnect the 12 V vehicle battery when the ignition is on or the engine is running.

NOTICE

If accessories that provide power for charging the 12 V vehicle battery are connected to the 12 V socket, this could

damage the electrical system or electronic components, resulting in electrical malfunctions.

Never connect accessories that provide power, such as solar panels or battery chargers, to the 12 V socket in

order to charge the 12 V vehicle battery.

Troubleshooting

Please read the introductory information and heed the Warnings and Notice ⇒

hood space.

Safety precautions for working in the

12-volt power supply

The red warning light turns on.

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Do not continue driving! Possible failure of the electrical system.

A message is shown in the instrument cluster display.

1. Stop the vehicle immediately and park it safely.

2. Turn off electrical equipment that is not needed.

3. Stop the engine and switch the ignition off.

4. Contact an authorized Volkswagen dealer or authorized Volkswagen Service Facility for assistance.

If the red warning light comes on, the start-stop system is switched off. The start-stop system will only be automatically

switched on again after the engine is restarted.

12-volt power supply

The yellow indicator light turns on.

A message regarding the battery charge level of the 12 V vehicle battery is shown in the instrument cluster display.

1. Let the engine run so that the 12 V vehicle battery can be recharged.

2. If the message about the battery charge level of the 12 V vehicle battery does not turn off after a few minutes despite the

measures having been taken, then contact an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

A message regarding the 12 V power supply is shown in the instrument cluster display.

1. Contact an authorized Volkswagen dealer or authorized Volkswagen Service Facility for assistance.

If the yellow indicator light lights up, the start-stop system will not be able to start the engine. If the yellow indicator light has

turned off, the 12 V vehicle battery has a sufﬁcient battery charge level to automatically restart the engine.

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Checking and filling -> 12 V vehicle battery for Your Volkswagen Jetta 4 Door Seventh Generation (2019-2025)

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