Checking intake manifold flap motor: VW 1.9 SDI (AGP, AGR, ALH, AQM, …)
Step-by-step checking intake manifold flap motor for the VW 1.9 SDI: factory workshop text. What to remove, in what order, and what to check after.
Workshop procedure for VW — the factory write-up, straight from real workshop data.
📐 34 workshop diagrams for AGP
Real factory drawings for this job — timing marks, bolt locations and routing. Locked in the free view.
📋 Procedure
AGR ALH AQM ASV AYQ
Engine code AYQ
Special tools, workshop equipment, testers, measuring instruments and auxiliary items required
Fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3
Test box V.A.G 1598/31
Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
Adapter set V.A.G 1594
Current flow diagram
Test sequence
Connect fault reader V.A.G 1551 (V.A.G 1552) and select engine electronics control unit with the "Address word" 01. When doing this the engine must be running at idling speed.
(Connecting fault reader and selecting engine electronics control unit => Page
01-4.)
Rapid data transfer
HELP
Select function XX
Indicated on display:
Press keys 0 and 3 for the function "Final control diagnosis".
Rapid data transfer (Q)
03 Final control diagnosis
Indicated on display:
Confirm input with Q key.
Final control diagnosis
⇒
Intake manifold flap motor V157
Indicated on display:
Activating the intake manifold flap motor changes the combustion noise (the positioning motor opens and closes the intake manifold flap).
If no changes to combustion noises can be heard:
Press C key.
Press keys 0 and 6 for the "End data transfer" function and confirm input with the Q key.
Switch off ignition.
Test sequence
Pull connector -1- off intake manifold flap motor -2-.
Switch on ignition.
Measure supply voltage at intake manifold flap motor contact 4 and at engine earth, then at contact 4 and 1 of connector.
Specification: approx. battery voltage
If the specification is not obtained:
Switch off ignition.
Connect test box V.A.G 1598/31 to control unit wiring harness.
Check wiring between test box and connector for open circuit using current flow diagram.
Contact 2+ socket 3
Contact 3+ socket 49
Wire resistance: max. 1.5ω
Additionally check wires for short to one another, to vehicle earth and to battery positive.
Specification: ∞ω
If no fault is detected in the wiring:
Renew Diesel direct injection system control unit (J248) => Page
23-134.
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.
Ask about my car →Other VW procedures
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- Dismantling and assembling intake manifold
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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 → · How these pages are made →Workshop data on this page last updated 20 Sep 2026.