S5 Quattro Coupe V8-4.2L (CAUA) (2009)
Oxygen Sensor: Testing and Inspection
Heated Oxygen Sensor 1, Checking
Heated Oxygen Sensor 1, Checking
The following procedure is used to diagnose Heated Oxygen Sensor (HO2S) (G39) 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) (G39).
Special tools, testers and auxiliary items required
‹› Multimeter.
‹› Wiring diagram.
Test requirements
‹› Fuse (SC2) OK.
‹› The Oxygen Sensor (O2S) Heater (Z19) 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.