Connecting vehicle diagnosis, testing and information system VAS 5051 and selecting engine electronics control unit — VW
Connecting vehicle diagnosis, testing and information system VAS 5051 and selecting engine electronics control unit on VW: factory workshop procedure.
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
Connecting
vehicle diagnosis, testing and information system
VAS 5051
and selecting engine electronics control unit
All functions previously carried out with the
fault reader
V.A.G 1551
and
vehicle system tester
V.A.G 1552
can also be carried out with the
vehicle diagnosis, testing and information system
VAS 5051
in vehicle self-diagnosis mode:
Operating instructions for
vehicle diagnosis, testing and information system
VAS 5051
.
Special tools and workshop equipment required
Vehicle diagnosis, testing and information system
VAS 5051
Test prerequisites
Fuses No. 15, 23, 24, 32 and 37 must be OK.
The battery voltage must be at least 11.5 V.
Earth connections between engine and body must be OK.
All electrical consumers, e.g. lights and rear window heating, must be switched off.
Procedure
Connect
vehicle diagnosis, testing and information system
VAS 5051
with
diagnosis cable, 5m
VAS 5051/1
or
diagnosis cable for LT2
VAS 5051/3
as follows:
Remove ashtray
1
.
Connect diagnosis cable connector on to diagnosis connection.
Depending upon desired function: Switch ignition on or start engine
Chapter
, table
“Selectable functions”
.
Note
The display fields will be displayed from top to bottom in functions 04 - Basic settings or 08 - Read data block.
If the display does not indicate as described in the work sequence:
Operating instructions for
vehicle diagnosis, testing and information system
VAS 5051
.
Indicated on display:
Select operating mode:
Press key on display for
“Vehicle self-diagnosis”
arrow
.
Indicated on display:
Select vehicle system:
Press
“01 - Engine electronics”
on the display
arrow
.
On the display the control unit identification and coding are displayed, e.g.:
If the coding differs from the vehicle version, then:
Check control unit coding
Chapter
, Coding engine control unit.
Indicated on display:
Select diagnostic function:
At this point all diagnostic functions are available.
Press the desired function on the display.
Further measures see repair procedures.
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.