Audi Workshop Service and Repair Manuals

Identify an inoperative or misfiring cylinder as follows:

• ‒ Unplug the connectors from the injectors in sequence with the engine running, and observe how the engine runs.

• or

• ‒ Compare the spark plugs of all cylinders with each other and check for soot on the electrodes.

If the defective cylinder has been identified:

• ‒ Connect a hand held multimeter for resistance measurement to the spark plug connector.

• Specified value: approx. 2 kω

If the specified value is not achieved:

• ‒ Replace the spark plug connector.

If the specified value is achieved:

• ‒ Replace the spark plug of the defective cylinder with one from another cylinder.

If the fault moves with the spark plug:

• ‒ Replace the spark plug.

If the fault remains in the same cylinder:

• ‒ Replace the ignition coil from the defective cylinder with one from another cylinder.

If the fault moves with the ignition coil:

• ‒ Replace the ignition coil.

If the fault remains in the same cylinder:

Check the earth connection for the ignition coil

• ‒ Unplug the connector from the ignition coil.

• ‒ → Check the earth connection from contact 4a on the 3 pin connector to the engine earth for an open circuit or short to positive.
• ‒ If necessary, rectify open circuit or short circuit.

If the earth connection is OK:

Check the power supply to the ignition coil

• ‒ → Connect the multimeter for voltage measurement to contact 15 on the connector and the earth.
• ‒ Switch on the ignition.

• Specified value: approx battery voltage

If the specified value is not achieved:

• ‒ Check the wiring.

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

If the specified value is achieved:

Checking actuation

• ‒ Remove the 4-pin connector from the power output stage => Overview of fitting locations - Page 24-5.

• ‒ Switch on the ignition.

• ‒ → Connect the V.A.G 1527 diode test lamp to the following contacts on the connector:

If the specified values are not achieved:

• ‒ Switch the ignition off.

• ‒ → Unplug the 3 pin connector on the relevant ignition coil.

• ‒ Check the wiring between the power output stage and contact 1 on the relevant ignition coil connector for an open circuit.

• ‒ If necessary, rectify open circuit or short circuit.