Checking exhaust gas recirculation valve N18 - vehicles with engine code letters AJM — AUDI

Checking
exhaust gas recirculation valve
N18
- vehicles with engine code letters AJM
Special tools and workshop equipment required
Hand-held multimeter
V.A.G 1526 A
or
V.A.G 1526 B
Voltage tester
V.A.G 1527 B
Adapter set
V.A.G 1594 A
or
V.A.G 1594 C
Test box
V.A.G 1598/31
Vehicle diagnostic, testing and information system
VAS 5051 A
with
diagnosis lead
VAS 5051/1
Checking internal resistance
Disconnect connector
1
from
exhaust gas recirculation valve
N18
Item 2
.
Connect
hand-held multimeter
V.A.G 1526 A
or
V.A.G 1526 B
to valve to measure resistance.
Specification: 14 ... 20 Ω
Note
At room temperature the resistance is in the lower tolerance range; at operating temperature it is in the upper tolerance range.
If specification is not reached:
Renew
exhaust gas recirculation valve
N18
.
Checking voltage supply
Connect
hand-held multimeter
V.A.G 1526 A
or
V.A.G 1526 B
to contact
2
and earth to measure voltage.
Switch on ignition.
Specification: approx. battery voltage
If specification is not reached:
Check for open circuit in wiring (see current flow diagram) and repair if necessary.
Checking activation
Connect
voltage tester
V.A.G 1527 B
between contacts
1
and
2
.
Vehicle diagnostic, testing and information system
VAS 5051 A
with
diagnosis lead
VAS 5051/1
is connected; vehicle self-diagnosis and vehicle system
“01 - Engine electronics”
is selected. When doing this the ignition must be switched on.
Display on
VAS 5051 A
:
From the selection menu
1
select the diagnostic function
“03 - Final control diagnosis”
.
Press the button
→
repeatedly until the
exhaust gas recirculation valve
N18
is actuated.
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
←
button to exit from function
“03 - Final control diagnosis”
.
Press
“06 - End output”
.
Switch off ignition.
If LED does not react as described:
Connect
test box
V.A.G 1598/31
to connectors of wiring harness; do not connect engine control unit. Connect earth clamp of test box to earth (not shown in illustration)
TDI injection and glow plug system (4-cyl.)
Rep. Gr.
23
.
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
Test box
V.A.G 1598/31
Socket
1
61
2
1 or 2
Repair wiring connection if necessary.