Volkswagen Workshop Service and Repair Manuals

Checking variable intake manifold flap change-over valve -N239- Special tools and workshop equipment required t  Hand multimeter -V.A.G 1526C- or multimeter -V.A.G 1715- t  Adapter set -V.A.G 1594C- t  Adapter cable, 121-pin -V.A.G 1598/31- t  Current flow diagram Test prerequisites

l  Fuses must be OK. l  The battery voltage must be at least 11.5 V. l  All electrical consumers, e.g. lights and rear window heating, must be switched off. Test procedure

–  Pull 2-pin connector off variable intake manifold flap change-over valve -N239--arrow-.

–  Measure resistance between change-over valve contacts. Specification: 25.0…45.0 Ω If the specification is not achieved: –  Renew inlet connection together with variable intake manifold flap change-over valve -N239- → Chapter, Removing and installing inlet connection. –  Read fault memory, if necessary, repair any faults and then clear fault memory → Chapter, Reading and clearing fault memory. If the specification is attained:

–  Set hand multimeter -V.A.G 1526C- or multimeter -V.A.G 1715- to measure voltage and connect to contacts 1 + 2 of disconnected connector for variable intake manifold flap change-over valve -N239-. –  Start engine and run at idling speed. Specification: approx. battery voltage –  Switch off ignition. The voltage value must fall to 0.0 V after approx. 3 seconds. If the voltage values do not change as described:

–  Connect adapter cable, 121-pin -V.A.G 1598/31- to control unit wiring harness. The engine control unit remains disconnected.

–  Check wiring between adapter cable, 121-pin -V.A.G 1598/31- and connector for open circuit referring to current flow diagram. Contact 1 + socket 1 Contact 1 + socket 2 Contact 2 + socket 62. Cable resistance: max. 1.5 Ω. –  Also check wiring for short to one another, short to vehicle earth and short to battery positive. Specification: ∞ Ω. If no fault in lines is detected: –  Renew engine control unit → Chapter.