A8L Quattro Sedan W12-6.0L (BSB) (2005)
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Check wires for short circuit to B+ and Ground (GND). Specification: infinite ohms
If no malfunction is detected in the wiring:
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Replace respective oxygen sensor:
‹› Heated Oxygen Sensor (HO2S) (G39), refer to Repair Manual.
‹› Heated Oxygen Sensor (HO2S) 2 (G108),
‹› Heated Oxygen Sensor (HO2S) 3 (G285),
‹› Heated Oxygen Sensor (HO2S) 4 (G286),
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Erase DTC memory of Engine Control Module (ECM) => [ Diagnostic Mode 04 - Erase DTC Memory ] See: Powertrain Management/Computers
and Control Systems/Testing and Inspection/Scan Tool Testing and Procedures/Diagnostic Modes 01 - 09, Diagnostic mode 4: Reset/erase
diagnostic data.
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Generate readiness code => [ Readiness Code, Generating ] See: Powertrain Management/Computers and Control Systems/Testing and
Inspection/Monitors, Trips, Drive Cycles and Readiness Codes.
Oxygen Sensors and Oxygen Sensor Regulation after Catalytic Converter, Checking
‹› When servicing terminals 3 and 4 in harness connector of oxygen sensors, use only gold-plated terminals.
Special tools, testers and auxiliary items required
‹› Hand multimeter (V.A.G 1526) or Multimeter (V.A.G 1715)
‹› Test adapter kit (V.A.G 1594)
‹› Wiring diagram
Test Conditions
‹› Motronic Engine Control Module (ECM) Power Supply Relay (J271) -position 4- must be OK, check:
‹› Battery voltage (both batteries) must be at least 11.5 Volts.
‹› All electrical consumers such as, lights and rear window defroster must be switched off.
‹› For vehicles with automatic transmission, selector lever must be in " P".