A8L Quattro Sedan W12-6.0L (BSB) (2005)
Air Flow Meter/Sensor: Testing and Inspection
Diagnostic Procedures
Mass Air Flow Sensor, Checking
‹› Use only gold-plated terminals when servicing terminals in harness connector of Mass Air Flow (MAF) sensors.
Special tools, testers and auxiliary items required
‹› Hand multimeter (V.A.G 1526) or Multimeter (V.A.G 1715)
‹› Test adapter kit (V.A.G 1594)
‹› Wiring diagram
Test conditions
‹› Motronic Engine Control Module (ECM) Power Supply Relay (J271) -position 4- must be OK, check:
‹› Battery voltage (both batteries) must be at least 11.5 Volts.
‹› All electrical consumers such as, lights and rear window defroster must be switched off.
‹› For vehicles with automatic transmission, selector lever must be in " P".
‹› Parking brake must be engaged.
‹› The Ground (GND) connections between engine and body must be OK.
‹› Coolant temperature must be at least 80°C => [ Diagnostic Mode 01 - Read Current System Data ] See: Computers and Control Systems/Testing
and Inspection/Scan Tool Testing and Procedures/Diagnostic Modes 01 - 09, Diagnostic mode 1: Check measured values; PID 5, Coolant
temperature.
‹› Fuses in right instrument panel fuse holder must be OK:
Right instrument panel fuse holder
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: Check measured values".
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Select measured value "PID 16: Air flow quantity at mass air flow sensor".