to store brake fluid. These containers could cause
It is forbidden to light a fire, cause sparks,
use an open flame or smoke!
confusion and someone could drink their contents, even
if they had been marked accordingly.
When charging the 12-volt battery, a highly
explosive detonating gas mixture is produced!
· Always store brake fluid in the original container tightly closed
and out of the reach of children.
Always keep children away from the
electrolyte of the 12-volt battery and from it!
WARNING
Always take the instruction manual into
account!
Brake fluid damages vehicle paint, plastic parts and tires if it
comes in contact with them. If brake fluid is spilled or leaked
onto vehicle parts, wipe it up immediately.
WARNING
Working on the 12-volt battery and electrical system can
cause severe burns, fire, and electric shock. Before working
on the battery, always read and observe the following warnings
and safety precautions:
Brake fluid can contaminate the environment. If any
operating fluid leaks, collect it and dispose of it properly.
· Before carrying out work on the battery
12 volts, switch off the ignition and all electrical consumers,
and disconnect the negative cable from this battery.
12 volt battery
Introduction to the topic
· Always keep children away from the electrolyte of the 12-
volt battery and from it.
The 12-volt battery is part of the electrical system and is
responsible for powering the vehicle.
· Always wear eye protection and protective gloves.
· The battery electrolyte is very aggressive. May cause skin
burns and blindness. When handling the 12 volt battery,
especially protect your hands, arms and face from possible
splashes of acid.
Only carry out work on the electrical system yourself if you
are familiar with the necessary operations and the generally
applicable safety measures, and if you have the appropriate
tools, media and operating fluids. Improper work can lead to
serious injuries ÿ . Have all work carried out by a specialized
· Do not smoke while carrying out the work and never carry
PY
it out near naked flames or sparks.
C
workshop. Volkswagen reco
O
mmends going to a Volkswagen
dealer for this.
· Avoid sparks from electrostatic discharges, as well as
when handling cables and electrical devices.
At the end of the chapter, in the troubleshooting section, you
will find information about warning and control lights that come
on ÿ p. 333.
· Never short-circuit the battery poles.
· Never use damaged 12 volt batteries. They could explode.
If the 12 volt battery is damaged, replace it immediately.
12 volt battery location
Depending on the equipment, the 12-volt battery can be located
in the engine compartment or in the trunk or behind a cover.
· Never use a frozen 12 volt battery. When the battery is
discharged, it can freeze at temperatures close to 0 °C
(+32 °F). If the 12 volt battery is frozen, replace it
immediately.
Explanation of 12 volt battery warning symbols
Always wear eye protection!
Battery electrolyte is highly corrosive.
Always wear protective gloves and eye
protection!
· If the vehicle has a 12-volt battery in the boot, make sure
that the degassing hose is correctly attached to the battery.
3 G 0 0 1 2 7 6 0 A H
12 volt battery
329
The battery can freeze and as a result
cia, damage irreparably.
WARNING
Do not expose the 12 volt battery to prolonged direct
sunlight.
After starting the engine with a deeply discharged
or recently replaced 12-volt battery, or after using
the starting aid, some system settings (time, date,
custom comfort settings, and programmings) may not
work. ) have been misadjusted or erased. Check and
correct these settings when the battery is sufficiently
charged.
· Ultraviolet rays can damage the battery casing.
WARNING
If you are not going to use the vehicle for a long time,
protect the 12 volt battery from frost.
Check the electrolyte level of the 12 volt battery
Note and , on page 315, and and , at the beginning of this chapter, on page 329.
Fig.238
In the engine compartment, in the boot: lift the dust cover of the 12 volt battery,
remove the 12 volt battery cover.
Vehicles with independent heating ÿ p. 129 and
those with the 12 volt battery in the trunk are equipped
with special batteries. The electrolyte level cannot be
checked on these batteries for technical reasons. To
check the 12 volt battery, go to a specialized workshop.
Previous steps
— Prepare the vehicle for work on the engine
compartment ÿ p. 315.
— Open the engine hood ÿ p. 317.
Open the 12 volt battery cover
To open the cover, lift it in the direction of the arrow
Fig. 239 Sight glass at the top of the 12 volt battery (schematic
ÿ fig. 238 .
representation).
To close the cover, lower it in the opposite direction of
the arrow ÿ fig. 238 .
The electrolyte level of the 12 volt battery should be
checked regularly when the mileage is high, in countries
with a hot climate and in the case of old batteries. The
battery does not require further maintenance.
330
check and reset
Battery electrolyte level is correct
to.
Removing and installing the 12 volt battery cover
Black
(battery in the trunk)
— Open the tailgate ÿ p. 85.
WARNING
— The 12-volt battery is located on the male
womb, behind a cover ÿ fig. 238 .
Working on the 12-volt battery can cause severe burns,
explosions, and electrical shock.
— To remove the cover, pull it in the direction of the arrow and
remove it upwards ÿ fig. 238 .
· Always wear eye protection and protective gloves.
— To mount the cover, place it in the original position in the
· The battery electrolyte is very aggressive. May cause skin
burns and blindness. When handling the 12 volt battery,
especially protect your hands, arms and face from possible
splashes of acid.
opposite direction of the arrow ÿ fig. 238 .
Check battery electrolyte level (12 volt batteries with sight
glass)
· Never tip over the 12 volt battery. Electrolyte could escape
from the degassing holes and cause burns.
— Make sure you have good lighting so that you can clearly see
the color indicator in the round peephole on the top of the 12-
volt battery ÿ fig. 239. Never use an open flame or incandescent
objects for lighting.
· Never open the 12 volt battery.
· If electrolyte is splashed on the skin or in the eyes, rinse
the affected part immediately with plenty of cold water for
a few minutes. Then see a doctor immediately.
— The round peephole indicator varies in color depending on
function of the battery electrolyte level.
Light yellow or colorless The battery electrolyte level is too low.
Go to a specialized workshop, have the battery checked
and, if necessary, replaced.
· In case of ingesting electrolyte, go immediately
to a doctor.
power and safety that must be met. The degassing hole of the 12
volt battery must always be on the negative pole side. The
degassing hole on the positive pole side must always be closed.
Charge, replace, and disconnect
or reconnect the 12-volt battery
Note and , on page 315, and and at the beginning of this
,
chapter, on page 329.
Only use maintenance-free 12 volt batteries that comply with
the TL 825 06 and VW 7 50 73 standards. These standards
If you suspect that the 12 volt battery is damaged or defective,
must be from October 2014 or later.
go to a duly qualified specialized workshop and request a review
of it.
Always have the 12 volt battery replaced by a qualified
specialist workshop, as the electronic system of the vehicle
Charging the 12-volt battery To
must be adapted when changing it. Only duly qualified specialist
workshops have the corresponding technology to carry out the
adaptation correctly. Volkswagen recommends having the
battery replaced by a Volkswagen dealer.
charge the 12-volt battery, go to a specialized workshop, since
the battery model that the vehicle incorporates from the factory
uses a technology that requires a limited voltage charge ÿ .
Volkswagen recommends going to a Volkswagen dealer for this.
Disconnect the 12 volt battery
Replace 12 volt battery
If you have to disconnect the 12-volt battery from the vehicle's
The 12 volt battery has been designed based on its location and
electrical system, note the following:
has safety features. If the battery needs to be replaced, check
with a Volkswagen dealer about electromagnetic compatibility,
size and maintenance requirements before purchasing a new
— Disconnect all electrical consumers and the ignition.
3 G 0 0 1 2 7 6 0 A H
one.
12 volt battery
331
Battery disconnection in case of accident with
— Before disconnecting the battery, unlock the vehicle;
otherwise the alarm will be triggered.
Airbag triggering In
vehicles with a 12-volt battery in the boot, if the airbags are
triggered in an accident, the electrical connection to the battery
is automatically interrupted pyrotechnically. In this way a short
circuit is avoided.
— Disconnect the negative cable first, then
nuation, the positive ÿ .
Connect the 12 volt battery
— Disconnect all electrical consumers and the ignition before
reconnecting the battery.
Factors by which the 12 volt battery is discharged
— Connect the positive cable first, then the negative ÿ .
— Prolonged stops without starting the engine
cha, especially if the ignition is left on.
After connecting the 12 volt battery and switching on the ignition,
various indicator lights may light up. These warning lights go off
after a short journey at a speed between approx. 15 and 20 km/
h (10 and 12 mph). If the warning lights do not go off, go to a
specialized workshop and have the vehicle checked.
— Use of electrical consumers with the mo
tor off.
— Independent heating in operation ÿ p. 129.
WARNING
If the 12-volt battery has been disconnected for a long period of
If the 12-volt battery is fixed incorrectly or the wrong
batteries are used, it may cause a short circuit, fire and
time, it may not correctly indicate or calculate when the next
service is due ÿ p. 19. In this case, the maximum permitted
maintenance intervals must be taken into account ÿ p. 364.
serious injury.
you see.
Use only maintenance-free 12 volt batteries.
and anti-spill system having the same properties,
specifications and dimensions as the factory-mounted
battery.
Vehicles with the "Keyless Access" keyless entry and start
system ÿ p. 77: If the ignition cannot be switched on after
connecting the 12 volt battery, lock and unlock the vehicle from
· If the vehicle has a 12-volt battery in the boot, make sure
outside. Then try again to switch on the ignition. If the ignition
does not switch on, seek the help of specialized personnel.
that the degassing hose is correctly attached to the battery.
Make sure that there is no open degassing hole in the
positive pole area. If there is an open degassing hole in
that area, close it with a plug. The degassing hose must be
connected to the open degassing hole in the negative pole
area.
Automatic disconnection of consumers
In the event of excessive stress on the 12-volt battery, the
intelligent on-board network management system automatically
applies certain measures to prevent its discharge:
WARNING
— The idling speed is increased so that the alternator supplies
more current.
When charging the 12-volt battery, a highly explosive
detonating gas mixture is produced.
— If necessary, the power of the most powerful consumers is
limited or, in an emergency, they are completely switched off.
· Charge the 12 volt battery only in
well ventilated places.
— When the engine is started, the power supply to the 12-volt
socket and the cigarette lighter may be briefly interrupted.
· Never charge a 12 volt battery that is frozen or thawed.
When the battery is discharged, it can freeze at
temperatures close to 0°C (+32°F).
On-board power management cannot always prevent the 12-
volt battery from discharging.
· If the 12 volt battery has frozen, replace it without fail.
This is the case if, for example, the ignition is left on with the
engine off or the position or parking light on for a long time.
· If the wires are connected to the poles incorrectly, a short
circuit may occur.
The positive cable is connected first, followed by the
negative.
332
check and reset
WARNING
· Never disconnect or connect the battery
12 volts when the ignition is on or the engine is
running. Also, never use a 12-volt battery that
does not meet the specifications for the vehicle's
battery. The electrical system or certain electronic
components may be damaged and electrical
functions may fail.
· Never connect to the mains socket
12-volt plug or cigarette lighter power-supplying
accessories, such as solar panels or battery
chargers, to charge the 12-volt battery. Doing so
could damage the vehicle's electrical system.
The battery may contain toxic substances,
such as sulfuric acid and lead. Dispose of the
12 volt battery in accordance with current regulations.
The electrolyte can contaminate the
environment. If any operating fluid leaks, pick
it up and dispose of it properly.
Problems and solutions
Note and , on page 315, and and at the
,
beginning of this chapter, on page 329.
alternator failure
The control indicator lights up red.
The alternator will not charge the 12 volt battery
while running.
— Disconnect electrical consumers that are not
are necessary.
— Inform a specialized workshop.
— Request a check of the electrical system.
The Start-Stop system cannot start the engine ÿ p.
144.
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333
2024 VW Passat Owner's Manual
VW Passat B7 Service & Repair Manual
VW Passat B6 Service & Repair Manual
