1996 AUDI A4 display

01-67


Combustion misfiring on several or all cylinders
stored in the DTC memory

- Leaks in intake system check intake system for air
leaks - Fuel pressure not OK check system and residual
pressure page 24
-20

- Exhaust gas recirculation too high check EGR system
hoses and components - Carbon deposits on fuel injectors check- Carbon deposits on intake valves check

Malfunction cause found: Yes


- Erase DTC memory, test drive and check DTC memory
Notes:

The malfunction "P0300 / 16684" is set as soon as combustion misfiring has been recognized on one or more cylinders.
If there is combustion misfiring with low misfiring rate, the MIL is only switched on after two successive trips without
preceding cold start and malfunction occurring.
Combustion misfiring with high misfiring rate is displayed immediately by the MIL light blinking since the Three Way
Catalytic Converter (TWC) can be damaged. In this case, driving should continue with reduced power and the malfunction
should be repaired as quickly as possible.
Pa
ge 91 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-70

Output on GST and/or on
VAG 1551 scan tool Possible malfunction cause

Malfunction repair
P0327 / 16711
Knock Sensor 1 Circuit Low
Input (Bank 1 or Single
Sensor) Malfunction P0332 / 16716
"Knock Sensor 2 Circuit Low Input"
Also in DTC memory
No
Yes

- Check knock sensor 1 -G61- and knock
sensor 2 -G66- page 28
-29


Malfunction cause found: Yes
No

- Erase DTC memory, test drive and check
DTC memory again
MIL Status:
MIL lights up immediately
Harness connector for Knock Sensor
(KS) 1 -G61- loose or corroded due to
moisture in the harness connector

- Check harness connector for tight fit and
contact corrosion, if necessary reconnect
and/or clean, installation location page 24
-1
For troubleshooting
Display group 015
Malfunction cause found: Yes
No

- Erase DTC memory, test drive and check
DTC memory again

Knock Sensor (KS) 1 -G61- loose

- Check mounting of knock sensor 1 -G61-
and if necessary retighten use insert
3247; tightening torque 20 Nm (15 ft lb)

Malfunction cause found: Yes
No

- Erase DTC memory, test drive and check
DTC memory again
Pa
ge 94 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-72

Output on GST and/or
on VAG 1551 scan tool
Possible malfunction cause

Malfunction repair
P0332 / 16716
Knock Sensor 2 Circuit
Low Input (Bank 2) Malfunction P0327 / 16711 "Knock
Sensor 1 Circuit Low Input (Bank 1 or
Single Sensor)" also in DTC memory
No
Yes

- Check knock sensor 1 -G61- and knock
sensor 2 -G66- page 28
-29


Malfunction cause found: Yes
No

- Erase DTC memory, test drive, and after
test drive, check DTC memory again
MIL Status:
MIL lights up
immediately
Harness connector for Knock Sensor
(KS) 2 -G66- loose or corroded due to
moisture in the harness connector

- Check harness connector for tight fit and
contact corrosion, if necessary reconnect
and/or clean, installation location page 24
-
1

Malfunction cause found: Yes
No

- Erase DTC memory, test drive and after test
drive, check DTC memory again
For troubleshooting
Display group 016
Knock Sensor (KS) 2 -G66- loose

- Check mounting of knock sensor 2 -G66-
and if necessary retighten use insert 3247;
tightening torque 20 Nm (15 ft lb)

Malfunction cause found: Yes
No

- Erase DTC memory, test drive and after test
drive, check DTC memory again
Pa
ge 97 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-76

Output on GST and/or on
VAG 1551 scan tool Possible malfunction cause

Malfunction repair
P0401 / 16785
Exhaust Gas Recirculation
Flow Insufficient Detected EGR system vacuum hose kinked or fallen
off

- Check vacuum hoses

Malfunction cause found: Yes
No

- Erase DTC memory, test drive and
after test drive, check DTC memory
again
MIL Status:
MIL lights up after 2 Trips Leak in a vacuum hose of the EGR system
(e.g. cracked, worn though, etc.)

- Check vacuum hoses for leaks

Malfunction cause found: Yes
No

- Erase DTC memory, test drive and
after test drive, check DTC memory
again

Vacuum hose between EGR vacuum
regulator solenoid valve -N18- and mechanical
EGR valve plugged

- Check vacuum hoses for
obstructions
For troubleshooting
Display group 017
Malfunction cause found: Yes
No
Continued next page

- Erase DTC memory, test drive and
after test drive, check DTC memory
again
Pa
ge 103 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-78

Output on GST and/or on
VAG 1551 scan tool Possible malfunction cause

Malfunction repair
P0402 / 16786
Exhaust Gas Recirculation
Flow Excessive Detected Vacuum line incorrectly connected
and/or hose connections transposed

- Check EGR system vacuum hose
according to vacuum plan page 24
-111


Malfunction cause found: Yes
No

- Erase DTC memory, test drive and after
test drive, check DTC memory again DTC
memory
MIL Status:
MIL lights up after 2 Trips EGR vacuum regulator solenoid
valve -N18- stuck in open position

- Check EGR vacuum regulator solenoid
valve -N18- page 24
-67


Malfunction cause found: Yes
No

- Erase DTC memory, test drive and after
test drive, check DTC memory again DTC
memory

EGR valve leaks or is stuck in
open position

- Check mechanical EGR valve page 24
-
70

For troubleshooting Display
group 017
Malfunction cause found: Yes


- Erase DTC memory, test drive and after
test drive, check DTC memory again
Notes:
Pa
ge 105 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-79

Output on GST and/or on
VAG 1551 scan tool Possible malfunction cause

Malfunction repair
P0422 / 16806
Main Catalyst Efficiency
Below Threshold (Bank 1) Are other malfunctions stored in the DTC
memory?

No

Yes

- First correct these malfunctions
according to Diagnostic Trouble Code
(DTC) table.
MIL Status:
MIL lights up after 2 Trips Malfunction cause found: Yes
No

- Erase DTC memory, test drive and
after test drive, check DTC memory
again

Bank 1 Three Way Catalytic Converter
(TWC) chemically or thermally aged or
mechanically destroyed

- Replace Three Way Catalytic
Converter (TWC) Bank 1
For troubleshooting
Display groups 035, 036,
044
Malfunction cause found: Yes


- Erase DTC memory, test drive and
after test drive, check DTC memory
again
Note:

With the help of the Oxygen Sensor Probe in front of and behind the Three Way Catalytic Converter (TWC), the rate of
Three Way Catalytic Converter (TWC) deterioration is determined using the Three Way Catalytic Converter (TWC) oxygen
storage capability.
Pa
ge 107 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-80

Output on GST and/or on
VAG 1551 scan tool Possible malfunction cause

Malfunction repair
P0432 / 16816
Main Catalyst Efficiency
Below Threshold (Bank 2) Are other malfunctions stored in the DTC
memory?

No

Yes

- First repair these malfunctions
according to Diagnostic Trouble Code
(DTC) table.
MIL Status:
MIL lights up after 2 Trips Malfunction cause found: Yes
No

- Erase DTC memory, test drive and
after test drive, check DTC memory
again

Bank 2 Three Way Catalytic Converter
(TWC) chemically or thermally aged or
mechanically destroyed

- Replace Bank 2 Three Way
Catalytic Converter (TWC)
For troubleshooting
Display groups 035, 036,
044
Malfunction cause found: Yes


- Erase DTC memory, test drive and
after test drive, check DTC memory
again
Note:

With the help of the Oxygen Sensor Probe in front of and behind the Three Way Catalytic Converter (TWC), the rate of
Three Way Catalytic Converter (TWC) deterioration is determined using the Three Way Catalytic Converter (TWC) oxygen
storage capability.
Pa
ge 108 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-82


EVAP canister purge regulator
valve -N80- sticks mechanically

- Check solenoid valve for Evaporative
Emission (EVAP) canister purge -N80- page 24
-58


Malfunction cause found: Yes
No
Continued next page

- Erase DTC memory, test drive and after test
drive, check DTC memory again
For troubleshooting
Display group 030
Sensor for EVAP canister -G172-
(differential pressure sensor) faulty

- Check Sensor for EVAP canister -G172-
(differential pressure sensor) page 24
-61


Malfunction cause found: Yes


- Erase DTC memory, test drive and after test
drive, check DTC memory again
Note:

With the help of the Sensor for EVAP canister -G172- (differential pressure sensor)the pressure is measured between the
Evaporative Emissions (EVAP) canister and solenoid valve for Evaporative Emission (EVAP) canister purge -N80- with
valve closed and open. If the difference in the two pressures is less than 4 mbar to 23 mbar (depending on air pressure),
the malfunction is set.
Pa
ge 110 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1