Audi Workshop Service and Repair Manuals

Testing operation

Test conditions

• ● Vehicle stationary, engine idling

• ‒ Read measured value block (function 08) and select Display Group 02 .

Display zone 2 shows the intake air mass (milligrams per stroke).

Specification: 100...280 mg/H (mg/stroke)

• ‒ If the values are not as specified or if the fault memory has recorded a fault relating to the air mass meter, test the power supply to the air mass meter => Page 24-40.

Testing power supply to air mass meter

• ‒ Test fuse for air mass meter.

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

• ‒ → If the fuse is OK, unplug the connector from -G70 and connect diode test lamp V.A.G 1527 between engine earth and contact 3 on the connector.
• ‒ Operate the starter briefly (engine can be allowed to start briefly). The diode test lamp should light up.
• ‒ → If the diode test lamp does not light up, test for open circuit and short to earth in the wiring between the fuse and contact 3 on the connector. If necessary, repair the wiring.

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

• ‒ If the fuse and the wiring are OK but the diode test lamp still does not light up, test the fuel pump relay => Page 24-33.
• ‒ If the power supply to the air mass meter is OK, test the signal wire => Page 24-41.

Testing signal wiring for air mass meter

• ‒ Connect test box V.A.G 1598/22 to wiring harness for engine control unit
  => Page 24-13.
• ‒ → Test wiring from plug connector on air mass meter...

• ‒ → ... to engine control unit for open circuit and short to positive or earth. Rectify if necessary.

• ‒ If the wiring is OK, fit a new air mass meter -G70.