A8 Quattro Sedan V8-4.2L (BGK) (2006)
Air Flow Meter/Sensor: Testing and Inspection
Diagnostic Procedures
Mass Air Flow Sensor, Checking
Mass Air Flow (MAF) Sensor (G70) is located in upper part of air filter housing.
‹› Use only gold-plated terminals when servicing terminals in harness connector of Mass Air Flow (MAF) sensor.
Special tools, testers and auxiliary items required
‹› Multimeter (VAG1526) or Multimeter (VAG1715)
‹› Connector test kit (VAG1594)
‹› Wiring diagram
Test Prerequisites
‹› The respective fuses of Mass Air Flow (MAF) Sensor (G70) must be OK:
‹› Fuel Pump (FP) Relay (J17) must be OK, check:
‹› Battery voltage must be at least 11.5 volts.
‹› All electrical consumers such as, for example, lights and rear window defroster must be switched off.
‹› Parking brake must be engaged or else daylight driving lights will be switched on.
‹› The parking brake button must be engaged in order to connect the electrical parking brake.
‹› If vehicle is equipped with an A/C system, it must be switched off.
‹› Ground (GND) connections between engine and chassis must be OK.
Function Test
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Connect diagnostic tester.
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Start engine and let run at idle.
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Under address word 33, select "Diagnostic mode 1: Checking measured values."
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Coolant temperature must be at least 80 °C "PID 5, Coolant temperature".
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Select measuring value "PID 16: Air flow quantity at Mass Air Flow (MAF) sensor".
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Check specified value of air flow quantity at Mass Air Flow (MAF) Sensor at idle: