Checking exhaust flap 1 valve N321: Audi 3.0 (ASN, AVK, BBJ)

Checking
exhaust flap 1 valve
N321
Special tools and workshop equipment required
Hand-held multimeter
V.A.G 1526C
Voltage tester
V.A.G 1527B
Auxiliary measuring set
V.A.G 1594C
Adapter cable, 121-pin
V.A.G 1598/31
(test box)
Vehicle diagnostic, testing and information system
VAS 5051B
with diagnosis lead
VAS 5051/1
Procedure
Open cover for storage compartment (left-side) in luggage compartment and detach.
Unplug connector
arrow
at
exhaust flap 1 valve
N321
.
Checking internal resistance
Connect
hand-held multimeter
V.A.G 1526C
to measure resistance between contacts of
exhaust flap 1 valve
N321
.
Specification: 22 ... 30 Ω.
If specification is not obtained:
Renew
exhaust flap 1 valve
N321
.
Checking voltage supply
Fuse for
exhaust flap 1 valve
N321
OK
Current flow diagrams, Electrical fault finding and Fitting locations
.
Fuel pump relay
J17
OK
Current flow diagrams, Electrical fault finding and Fitting locations
.
Note
The
exhaust flap 1 valve
N321
is supplied with power via the
fuel pump relay
J17
.
Connect
hand-held multimeter
V.A.G 1526C
to measure voltage between contact
2
of electrical connector for
exhaust flap 1 valve
N321
and earth
“–”
.
Operate the starter briefly.
Specification: approx. battery voltage
If specification is not obtained:
Repair wiring from contact
2
of connector for
exhaust flap 1 valve
N321
, via fuse to
fuel pump relay
J17
Current flow diagrams, Electrical fault finding and Fitting locations
.
If specification is obtained:
Checking activation
Vehicle diagnostic, testing and information system
VAS 5051B
connected with diagnosis lead
VAS 5051/1
.
Connect
voltage tester
V.A.G 1527B
between contacts
1
and
2
of electrical connector for
exhaust flap 1 valve
N321
.
Switch on ignition and select vehicle system
“01 - Engine electronics”
.
Repeat function
“03 - Final control diagnosis”
.
Press the
→
key repeatedly until the following display appears:
Display on
VAS 5051
(example):
A
Actuator is running; continued switching is allowed
6
Exhaust flap 1 valve
N321
LED should flash slowly
Note
Voltage testers with a low current draw do not go out completely between activation signals from engine control unit, but continue to glow slightly and become distinctly brighter on activation.
Press the
←
key to exit from function
“03 - Final control diagnosis”
.
Press function
“06 - End output”
.
Switch off ignition and unplug diagnostic connector.
If the LED does not flash:
Connect
adapter cable, 121-pin
V.A.G 1598/31
(test box) to connectors of wiring harness; do not connect engine control unit. Connect earth clip of test box to earth
Rep. Gr.
24
.
Caution
To prevent damage to electronic components, select appropriate measuring range before connecting measuring leads and observe test requirements.
Check for open circuit and short to positive or earth in the following wiring:
Connector
Contact
V.A.G 1598/31
Socket
1
19
Repair wiring connection if necessary.