Tiguan 2021 ➤, Tiguan RUS 2021 ➤
Brake system - Edition 10.2020
45 – Anti-lock brake system
1
General information
1.1
Repair instructions for repair work on
ABS
The ABS brake system is divided diagonally. The servo-assis‐
tance is effected pneumatically by the vacuum brake servo unit.
Vehicles with ABS are not fitted with a mechanical brake pres‐
sure regulator. Specially matched software in the control unit
regulates the brake force distribution on the rear axle.
NOTICE
Faults in the ABS do not influence the brake system and ser‐
vo assistance. The conventional brake system remains func‐
tional even without ABS. A change in braking behaviour is to
be reckoned with. After the ABS warning lamp comes on, the
rear wheels may lock prematurely during braking.
Location of anti-lock brake system on left-hand drive vehicle:
1 - ABS hydraulic unit -N55- and ABS control unit -J104-
2 - Brake servo
Location of anti-lock brake system on right-hand drive vehicle:
1 - Brake servo
2 - ABS hydraulic unit -N55- and ABS control unit -J104-
10
Rep. gr.45 - Anti-lock brake system
Tiguan 2021 ➤, Tiguan RUS 2021 ➤
Brake system - Edition 10.2020
The control unit and hydraulic are combined in a single compo‐
nent. They can be separated only when removed. Hydraulic
pump must not be separated from hydraulic unit either.
♦ Before carrying out repair work on the anti-lock brake sys‐
tem, determine the cause of the fault as well as the control
unit code using “Guided Fault Finding”.
“Fault finding” is performed with ⇒ Vehicle diagnostic tester.
♦ With ignition switched off, disconnect battery earth strap.
♦ Before carrying out welding work with an electric welding
unit, see ⇒ General Information; Body Repairs, General
Body Repairs.
♦ When working with brake fluid, observe the relevant safety
precautions and notes ⇒ page 126 .
♦ After work for which the brake system had to be opened,
bleed the brake system with brake filling and bleeding unit
-VAS 6860- ⇒ page 126 .
♦ During the final road test, ensure that a controlled brake
application is performed at least once. A pulsation of the
brake pedal must be noticeable.
♦ Absolute cleanliness is required when working on the anti-
lock brake system.
♦ Auxiliary items containing mineral oil, e.g. oils, greases, etc.
must never be used.
♦ Thoroughly clean all unions and adjacent areas before loos‐
ening. Do not use aggressive cleaning agents such as brake
cleaner, petrol, thinners or similar.
♦ Place removed parts on a clean surface and cover them
over.
♦ Carefully cover opened components or seal them if repairs
cannot be carried out immediately.
♦ Only use lint-free cloths.
♦ Remove packing from replacement parts immediately prior
to installation and not before.
♦ Only use parts from original packaging.
♦ Do not work with compressed air if the system is open. Do
not move the vehicle.
♦ The valve coils in the control unit cannot be adjusted.
♦ The valve coils in the control unit cannot be renewed.
♦ Pressure sensor must not be changed or damaged.
♦ The pressure sensor cannot be renewed.
♦ The sensor housing must not be exposed to mechanical
stress.
♦ No measurements must be taken on contact points of con‐
trol unit.
♦ No measurements must be taken on contact points of hy‐
draulic unit.
♦ Contact pins of hydraulic unit must not be bent or damaged.
♦ The contacts cannot be renewed.
♦ No contact sprays may be used on the contacts or the pres‐
sure sensor.
1. General information
11
Tiguan 2021 ➤, Tiguan RUS 2021 ➤
Brake system - Edition 10.2020
♦ Foreign bodies must not get between the control unit and the
hydraulic unit.
♦ The electronic control unit can be exposed to a maximum
temperature of 95°C for only a short period, and to a maxi‐
mum of 85°C for longer periods (approx. 2 hours). Ensure
that no brake fluid enters connectors.
12
Rep. gr.45 - Anti-lock brake system
2024 VW Tiguan Owner's Manual
