Audi Workshop Service and Repair Manuals

Electrical test of intake manifold changeover valve -N156

Fitting location =>Page 24-5.

• ‒ Unplug connector on intake manifold changeover valve.
• ‒ → Measure resistance at intake manifold changeover valve.
• ‒ Specification: 25 ... 35 ohm.

If the value is not as specified, fit a new valve.

Testing power supply to intake manifold changeover valve -N156

• ‒ → Unplug connector on intake manifold changeover valve.

• ‒ Connect diode test lamp V.A.G 1527 between engine earth and contact 1 (positive) on connector using cables from adapter set V.A.G 1594.
• ‒ Operate starter briefly (the engine can be allowed to start).

• Specification: The diode test lamp should light up.

If the diode test lamp does not light up, carry out the following tests:

• ‒ Test fuse for -N156.
• ‒ Test for open circuit in wiring between fuse and contact 1 on connector for intake manifold changeover valve using current flow diagram.

=> Current Flow Diagrams, Electrical Fault Finding and Fitting Locations

• Specification: max. 1 ohm

• ‒ Test fuel pump relay and activation
  =>Page 24-30.