S4 V8-4.2L (BHF) (2004)
-
Select the desired measuring value "PID 16: Air flow quantity at Mass Air Flow (MAF) sensor -G70-".
-
Specified value: 3.5 to 7.0 g/s
-
End diagnosis and switch ignition off.
If the specified value is not reached:
-
Check intake air system for leaks (false air). See: Computers and Control Systems/Testing and Inspection/Component Tests and General
Diagnostics/Intake System For Leaks (False Air), Checking
-
Check voltage supply and wire connections
If the specified value is exceeded:
-
Eliminate engine load via additional equipment (A/C system/power-assisted steering/generator).
-
Check voltage supply and wire connections
Checking voltage supply
-
Disconnect electrical harness connector -4- at Mass Air Flow (MAF) Sensor -G70-.
NOTE:
-
Depicted in illustration with air filter cover removed.
-
Disregard the other items as well as the arrow.
-
Connect multimeter for voltage measurement as follows.
Harness connector Terminal
Measure to
2
Engine Ground (GND)
-
Operate starter briefly (engine can also start).
-
Specified value: approx. battery voltage
-
Switch ignition off.
If specified value is not obtained:
-
Check wire connection from harness connector terminal 2 to Fuel Pump (FP) Relay -J17- via fuse for open circuit according to wiring diagram.
-
Specified value: Wire resistance max 1.5 Ohms
-
If necessary, repair wire connection.
If voltage supply is OK:
Check Ground (GND) activation