Checking intake manifold flap change-over — VW
Checking intake manifold flap change-over on VW: 19 steps, engines AGD, AGP, AGR, AHF. What to remove, in what order, and what to check after.
Workshop procedure for VW — the exact step sequence and torque figures, straight from real workshop data.
🧭 Before you start
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- The intake manifold flap must, after switching off ignition, close and after approx. 3 seconds open again.
- The voltage value must fall to 0 V after approx. 3 seconds.
📋 Procedure
- Start engine and run at idling speed.
- Switch off ignition.
- Observe positioning lever on intake manifold flap (2nd person required).
- The intake manifold flap must, after switching off ignition, close and after approx. 3 seconds open again.
- Check intake manifold flap change-over mechanics for freedom of movement. To do this, operate rods by hand.
- Check function of vacuum actuator with hand vacuum pump VAS 6213.
- Check that vacuum lines are connected correctly.
- Check variable intake manifold flap change-over valve N239.
- Pull connector off variable intake manifold flap change-over valve N239.
- Measure resistance between contacts of variable intake manifold flap change-over valve N239.
- Renew variable intake manifold flap change-over valve N239.
- Set multimeter to measure voltage and connect to contacts 1 + 2 of disconnected connector from intake manifold flap change-over valve.
- Start engine and run at idling speed.
- Switch off ignition.
- The voltage value must fall to 0 V after approx. 3 seconds.
- Connect adapter cable, 121-pin V.A.G 1598/31 to control unit wiring harness.
- Check wiring between adapter cable, 121-pin V.A.G 1598/31 and connector for open circuit referring to current flow diagram.
- Also check wiring for short to one another, short to vehicle earth and short to battery positive.
- Renew diesel direct injection system control unit J248.
Other VW procedures
- Checking speedometer sender G22
- Servicing valve gear
- Renewing engine control unit – VW Passat B5
- Checking intake air temperature sender G42
- Checking injection timing device control range
- Removing engine · 41 torque figures
- Removing and installing camshaft – VW Golf Cabriolet · 47 torque figures
- Adjusting valve timing – VW Passat B5 · 83 torque figures
- Removing and installing camshafts – VW Passat B6 · 39 torque figures
- Removing and installing coolant pump · 53 torque figures
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.