Audi Workshop Service and Repair Manuals

Testing operation

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

Display zone 4 will show the intake air mass in grams per second.

Specification: 2.0....4.0 g/s

• ‒ If the value is not as specified or if the fault memory has recorded a fault related to the air mass meter, test the power supply to the air mass meter => Page 24-34.

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, connect diode test lamp V.A.G 1527 between engine earth and contact 3 on the plug 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 circuits or shorts to earth in wiring between fuse and contact 3 on plug connector. Rectify if necessary.

=> 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 24-28.
• ‒ If the power supply is OK, test the signal wiring
  => Page 24-35.

Testing signal wiring for air mass meter

• ‒ Connect test box V.A.G 1598/22 to wiring harness for engine control unit
  => Page 24-8.
• ‒ → 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.