warning AUDI A6 1999 C5 / 2.G ATQ Engine Motronic On Board Diagnostic Workshop Manual

01-2

If the ECM recognizes malfunctions that lead to
a degradation of emissions values, it indicates
them by lighting the Malfunction Indicator Lamp
(exhaust warning lamp -K83-). Clarification of
this lamp Page 01
-3 .

"E-Gas"-relevant malfunctions are also
indicated in the instrument cluster by the
warning lamp for Electronic Power Control
("EPC warning lamp").
Pa
ge 2 of 19 Motronic, On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.01.1

01-5

Function test of warning lamp

- Switch ignition on.


Warning lamp for On Board Diagnostic
(Malfunction Indicator Lamp -MIL-) must
light up

A - Warning lamp for On Board Diagnostic
(Malfunction Indicator Lamp -MIL-) does not
light up

- Connect VAG1598/31 test box at wiring harness
to ECM, do not connect ECM Page 24
-17
.

- Bridge sockets 1 and 47 of test box.

- Switch ignition on.


Warning lamp must light up.
If warning lamp does not light up:

- Switch ignition off.

- Remove instrument cluster:

Pa
ge 5 of 19 Motronic, On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.01.1

01-7

B - Warning lamp for On Board Diagnostic
(Malfunction Indicator Lamp -MIL-) remains lit
constantly

- Check DTC memory of Engine Control Module
(ECM) Page 01
-15
.
If no DTCs are stored:

- Connect VAG1598/31 test box at wiring harness
to ECM, do not connect ECM Page 24
-17
.

- Remove instrument cluster:

Repair Manual, Electrical Equipment, Repair
Group 90, Instrument cluster, removing and installing


- Check the following wire connection for short
circuit to Ground (GND):

Test box
VAG1598/31
Socket
Instrument cluster

Terminal
47 Electrical Wiring Diagrams,
Pa
ge 8 of 19 Motronic, On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.01.1

01-8

Safety precautions

If special testing equipment is required during
road test, note the following:

WARNING!

Scan tools and testing devices must always
be secured on the rear seat and operated
from there by a second person.
If a scan tool or testing device were to be
operated from the passenger seat and there
were an accident involving activation of the
passenger-side airbag, the person seated
there could be seriously injured.
Pa
ge 10 of 19 Motronic, On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.01.1

01-10

WARNING!

Observe safety precautions Page 01
-8 .

Note:
The following description only explains
implementation of On Board Diagnostic using
VAG1551 Scan tool.
When using the VAS5051 tester, observe the
tester's instructions for use V.A.G - ON BOARD DIAGNOSTIC
HELP
1 - Rapid data transfer 1)2 - Blink code output 1
)

Indicated on display: 1) Operating modes 1 and 2 are displayed alternately
Note:
If nothing appears in display:
- Perform troubleshooting procedure after "troubleshooting procedure leak
test":
Electrical Wiring Diagrams, Troubleshooting & Component Locations
binder
Depending on desired function Table "Selectable functions", page
Page 01
-14
:
- Switch ignition on.
or
Pa
ge 13 of 19 Motronic, On Board Dia
gnostic
(OBD
)
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.01.1