A8 Quattro Sedan V8-4.2L (BVJ) (2008)
-
Install the test box.
If the manufacturers test box is not being used. Perform the following step.
-
Remove the Motronic Engine Control Module (ECM) (J623). Refer to => [ Engine Control Module, Removing and Installing ] See: Powertrain
Management/Computers and Control Systems/Engine Control Module/Service and Repair.
-
Using a multimeter, check the Mass Air Flow (MAF) Sensor (G70)/Intake Air Temperature (IAT) Sensor (G42) electrical harness connector
terminals to the Motronic Engine Control Module (ECM) (J623) electrical harness connector T94 terminals for an open circuit.
Specified value: 1.5 ohms max.
If the specification was not obtained:
-
Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).
-
Check the electrical harness connector for damage, corrosion, lose or broken terminals.
-
If necessary, repair the faulty wiring connection.
If no malfunction is detected in the wiring and if the voltage supply was OK:
-
Replace Mass Air Flow (MAF) Sensor (G70). .
If no malfunction is detected in the wiring and if the voltage supply was not OK:
-
Replace the Motronic Engine Control Module (ECM) (J623). Refer to => [ Engine Control Module, Removing and Installing ] See: Powertrain
Management/Computers and Control Systems/Engine Control Module/Service and Repair.
Assembly is performed in the reverse order of removal.
Final procedures
After repair work, the following work steps must be performed in the following sequence:
1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Scan Tool Testing and Procedures/Diagnostic Modes 01 - 09/Diagnostic Mode 03 - Read DTC Memory.