Checking modulating piston movement sender G149 and metering adjuster N146 — VW
Checking modulating piston movement sender G149 and metering adjuster N146 on VW: factory workshop procedure for engines AGD, AGP, AGR, AHF.
Workshop procedure for VW — the factory write-up, straight from real workshop data.
📐 18 workshop diagrams for AGD
Real factory drawings for this job — timing marks, bolt locations and routing. Locked in the free view.
📋 Procedure
Checking
modulating piston movement sender
G149
and
metering adjuster
N146
The
metering adjuster
N146
is an electromagnetic swivelling positioner which is actuated by the control unit via a specific duty cycle. The eccentric shaft on the
metering adjuster
N146
moves the modulating piston on the high-pressure piston and thereby determines the quantity of fuel injected.
The
modulating piston movement sender
G149
informs the control unit of the position of the
quantity adjuster
N146
and therefore stipulates the amount injected.
Special tools and workshop equipment required
Hand multimeter
V.A.G 1526C
or
multimeter
V.A.G 1715
Fault reader
V.A.G 1551
or
vehicle system tester
V.A.G 1552
with
diagnosis cable
V.A.G 1551/3
Adapter set
V.A.G 1594C
Adapter cable, 121-pin
V.A.G 1598/31
Current flow diagram
Test procedure
Connect
fault reader
V.A.G 1551
or
vehicle system tester
V.A.G 1552
and select engine electronics control unit with
“address word 01”
. Engine must be idling. (Connecting
fault reader
V.A.G 1551
and selecting engine electronics control unit
Chapter
).
Indicated on display:
Rapid data transfer HELP
Select function XX
Press keys
0
and
8
for function
“Read measured value block”
and confirm entry with
Q
key.
Indicated on display:
Read measured value block
Input display group number XXX
Press keys
0
,
0
and
1
for
“Display group number 1”
and confirm entry with
Q
key.
Indicated on display:
Read measured value block 1 ->
880 rpm 6.5 mg/stroke 1.680 V 87.3°C
Check coolant temperature in display zone 4. Specification: At least 85°C
Continue with check only if coolant temperature is achieved.
Check voltage of
modulating piston movement sender
G149
in display zone 3.
Read measured value block 1 ->
880 rpm 6.5 mg/stroke 1.680 V 87.3°C
Engine code AGD
Specification: 1.400…1.800 V
Engine code AKU
Specification: 1.500…2.100 V
Continuation for all engine codes
Press
→
key.
Press keys
0
and
6
for function
“End output”
and confirm entry with
Q
key.
Switch off ignition.
If specification is not achieved, check
modulating piston movement sender
G149
and
metering adjuster
N146
as described in following:
TorqFix answers live for your specific car — tell it the engine code and it serves the matching sequence, torque figures and wiring for that exact variant.
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Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com
The story behind TorqFix →Workshop data on this page last updated 20 Sep 2026.