S5 Quattro Coupe V8-4.2L (CAUA) (2009)
Oxygen Sensor: Testing and Inspection
Heated Oxygen Sensor 2, Checking
Heated Oxygen Sensor 2, Checking
The following procedure is used to diagnose Heated Oxygen Sensor (HO2S) 2 (G108) which is controlled by the Motronic Engine Control Module
(ECM) (J623).
‹› Use only gold-plated terminals when servicing terminals in the electrical harness connectors of the Heated Oxygen Sensor (HO2S) 2 (G108).
Special tools, testers and auxiliary items required
‹› Multimeter.
‹› Wiring diagram.
Test requirements
‹› Fuse (SB10) OK.
‹› The Oxygen Sensor (O2S) 2 Heater (Z28) before catalytic converter OK.
‹› Battery voltage at least 12.5 volts.
‹› All electrical consumers such as, lights and rear window defroster, switched off.
‹› A/C switched off.
‹› Ground (GND) connections between engine/transmission/chassis OK.
‹› Exhaust system between catalytic converter and cylinder head properly sealed.
‹› Coolant Temperature at least 80° C.
Function test
-
Perform the function test located in diagnostic mode 06. => [ Diagnostic Mode 06 - Read Test Results for Specific Diagnostic Functions ] See:
Computers and Control Systems/Testing and Inspection/Scan Tool Testing and Procedures/Diagnostic Mode 01 - 09/Diagnostic Mode 06 - Read
Test Results for Specific Diagnostic Functions.
If specified values are obtained:
-
End diagnosis and switch the ignition off.
If the specified values are not obtained:
Test procedure
-
Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] See: Computers and Control Systems/Testing
and Inspection/Scan Tool Testing and Procedures/Preliminary Check.
Start diagnosis
-
Remove the engine compartment trim.