A4 Quattro Cabriolet V6-3.2L (BKH) (2007)
Oxygen Sensor: Testing and Inspection
Oxygen Sensor Heaters Before Catalytic Converter, Checking
Oxygen Sensor Heaters before Catalytic Converter, Checking
This procedure is used to check Oxygen Sensor (O2S) Heater (Z19) or Oxygen Sensor (O2S) Heater ( Z28).
‹› When servicing terminals in harness connector of Heated Oxygen Sensors (HO2S), use only gold-plated terminals.
Special tools, testers and auxiliary items required
‹› Multimeter.
‹› Wiring diagram.
Test requirements
‹› The Heated Oxygen Sensor (HO2S) (G39) fuse OK.
‹› The Heated Oxygen Sensor (HO2S) 2 (G108) fuse OK.
‹› Battery voltage at least 12.5 volts.
‹› All electrical consumers such as, lights and rear window defroster, switched off.
‹› Vehicles with automatic transmission, shift selector lever into position " P" or "N".
‹› A/C switched off.
‹› Ground (GND) connections between engine/transmission/chassis OK.
‹› Ignition switched off.
Test procedure
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Perform a preliminary check to verify the customers complaint. Refer to => [ General Diagnosis ] See: Testing and Inspection/Initial Inspection
and Diagnostic Overview/General Diagnosis.
Start diagnosis
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Disconnect the Oxygen Sensor (O2S) Heater (Z19 ) electrical harness connector - 1 -.
To disconnect the Oxygen Sensor (O2S) Heater (-Z28-), perform the following steps:
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Remove the screw - arrow - retaining the coolant reservoir.