S4 Quattro Cabriolet V8-4.2L (BHF) (2008)
Specified value: 0.400 to 0.500 Volts
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Switch the ignition off.
If the specified value was not obtained:
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Replace the Heated Oxygen Sensor (HO2S) (G39) or the Heated Oxygen Sensor (HO2S) 2 (G108) Refer to Fuel Injection and Ignition Repair
Information.
If the specified value was obtained:
Checking wiring
If the manufacturers test box is being used. Perform the following step.
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Install the test box. Refer to Fuel Injection and Ignition Repair Information.
If the manufacturers test box is not being used. Perform the following step.
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Remove the Motronic Engine Control Module (ECM) ( J623). Refer to => [ Engine Control Module, Replacing ] See: Engine Control
Module/Service and Repair.
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Using a Multimeter, check the Heated Oxygen Sensor (HO2S) (G39) or the Heated Oxygen Sensor (HO2S) 2 (G108) electrical harness connector
terminals to the Motronic Engine Control Module (ECM) (J623) electrical harness connector T121 terminals for an open circuit.