Q7 Quattro V8-4.2L (BAR) (2008)
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Oxygen Sensor: Testing and Inspection
Oxygen Sensors and Oxygen Sensor Regulation after Catalytic Converter, Checking
Oxygen Sensors and Oxygen Sensor Regulation after Catalytic Converter, Checking
The following procedure is used to diagnose both Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) (G130) and the Oxygen
Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) (G131)
‹› When servicing terminals 3 and 4 in the electrical harness connector of the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter , use
only gold-plated terminals.
Special tools, testers and auxiliary items required
‹› Multimeter.
‹› Wiring diagram.
Test requirements
‹› The Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) (G130)and Oxygen Sensor (O2S) 2 Behind Three Way Catalytic
Converter (TWC) (G131) fuses Ok.
‹› Oxygen Sensor (O2S) 1 (behind Three Way Catalytic Converter (TWC)) Heater (Z29) and Oxygen Sensor (O2S) 2 (behind Three Way Catalytic
Converter (TWC)) Heater (Z30) OK.
‹› Battery voltage at least 12.5 volts.
‹› All electrical consumers such as, lights and rear window defroster, switched off.
‹› Vehicles with automatic transmission, selector lever in position " P" or "N".
‹› 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.
Test procedure
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Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] See: Powertrain Management/Computers and
Control Systems/Testing and Inspection/Scan Tool Testing and Procedures/Preliminary Check
Start diagnosis
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Connect scan tool.
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Start the engine and let it run at idle.
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Select "Diagnostic mode 6: Check test results of components that are not continuously monitored".
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Select "Test-ID 02: Oxygen sensor monitoring behind catalytic converter".
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Select following Test-IDs.
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Check the specified values at idle.
