Volkswagen Golf / Golf GTI / Jetta. Manual — part 95

26-21

- Generate readiness code again if DTC memory

has been erased or engine control module
disconnected from permanent positive supply:

Repair Manual, 2.8 Liter VR6 4V Fuel Injection

& Ignition, Engine Code(s): BDF, Repair Group
01

If no DTC is stored in DTC memory:

- Press keys 0 and 6 for function "End output" and

confirm entry with Q key.

- Switch ignition off.

- Replace front exhaust pipe with catalytic

converter

Page 26-6

, item - 14 -.

Exhaust system components, servicing

26-22

Significance of Malfunction
Indicator Lamp (MIL) for
exhaust emissions

If the engine control module detects
a malfunction it switches on the
Malfunction Indicator Lamp (MIL).

Location MIL

Note:

The MIL can switch on in the
continuous or flashing mode. Check
the DTC memory in every case:

Repair Manual, 2.8 Liter VR6 4V

Fuel Injection & Ignition, Engine
Code(s): BDF, Repair Group 01

Repair Manual, 2.8 Liter VR6 4V

Fuel Injection & Ignition, Engine
Code(s): BDF, Repair Group 01

Flashing mode: There is a

malfunction present which can
damage the catalytic converter
when continuing to drive at this
power output. If this occurs,
continue driving only at reduced
output.

Continuous mode: There is a

malfunction present which
causes the emissions to
deteriorate. Check the Motronic
engine control module and/or
transmission control module.

Check the DTC memory if the

customer has a complaint or if
there is a driving characteristic
problem and the MIL does not
light up. This is because
malfunctions can be stored which
will not switch on the MIL
immediately.

- Check function of Malfunction

Indicator Lamp (MIL):

Exhaust system components, servicing

26-23

Secondary air system

CAUTION!

When performing repair work, especially due
to the confined conditions in the engine
compartment, pay attention to the following:

Route all types of lines (e.g. for fuel,
hydraulics, EVAP system, coolant,
refrigerant, brake fluid and vacuum) as well
as electrical wiring so that the original
positions are restored.

Ensure sufficient clearance to all moving or
hot components.

Function

During cold starting the secondary air system

blows air in behind the exhaust valves. This
produces an oxygen rich exhaust gas, causes
afterburning and reduces the heating-up phase
of the catalytic converter. Activation is performed
by the Motronic Engine Control Module -J220-
via the Secondary Air Injection (AIR) pump relay
-J299- to the combi-valve.

Checking secondary air system

Page 26-31

.

Secondary air system

26-24

Components
of the
secondary air
system,
removing and
installing

Note:

Repair

Manual, 2.8 Liter
VR6 4V Fuel
Injection &
Ignition, Engine
Code(s) BDF,
Repair Group 01

Repair

Manual, 2.8 Liter
VR6 4V Fuel
Injection &
Ignition, Engine
Code(s) BDF,
Repair Group 01

Components

marked with
an * are
checked by
On Board
Diagnostic
(OBD):

Components

marked with
** are
checked by
output
Diagnostic
Test Mode
(DTM):

Secondary

Air Injection
(AIR) pump
relay -J299-
*

/

**

Fig. 1

,

Position of
relays in
protective
housing (on
left in engine

Secondary air system