A8 Sedan V8-3.7L (AEW) (1997)
Mass Air Flow Sensor: Testing and Inspection
Mass Air Flow (MAF) Sensor, Checking
The MAF sensor is located in the upper air cleaner housing.
Checking function
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Connect VAG1551 or VAG1552 Scan Tool (ST) and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (engine running at
idle). Refer "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG1551 or VAG1552 Scan Tool" See: Powertrain
Management/Computers and Control Systems/Testing and Inspection
Indicated on display
Rapid data transfer
HELP
Select function XX
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Press buttons -0- and -8- to select "Read Measuring Value Block" function 08, and press -Q- button to confirm input.
Indicated on display
Read Measuring Value Block
Input display group number XXX
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Press buttons -0-, -0- and -7- to input display group number 7 (007), and press -Q- button to confirm input.
Indicated on display
Read Measuring Value Block 7
->
1
2
3
4
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Check specified values for mass air flow sensor (display fields 1 and 2):
If the displayed values are not OK:
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Check intake air system for intake air system for leaks ("false air").
If there are no leaks:
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Check MAF sensor voltage supply.
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Press -> button to advance program sequence.
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Press buttons -0- and -6- to select "End Output" function 06, and press -Q- button to confirm input.
Checking MAF sensor -G70-
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Check fuse for MAF sensor (E-box in plenum).
If fuse is OK:
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Remove upper air cleaner housing.
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Disconnect MAF sensor harness connector.