Jetta L4-2.0L (AZG) (2004)
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Unscrew protective cover (arrows) and disconnect 4-pin harness connector (black) -1- to Heated Oxygen Sensor (HO2S) -G39- before catalytic
converter.
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Connect multimeter to terminals 3 + 4 of connector to Engine Control Module (ECM) for voltage measurement.
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Switch on ignition and measure primary voltage. Specified value: 0.400 to 0.500 Volts
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Switch ignition off.
If specified value is not obtained:
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Test oxygen sensor wires.
If specified value is obtained:
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Replace Heated Oxygen Sensor (HO2S) 1 Bank 1 -G39- before catalytic converter, item 9.
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Erase DTC memory of Engine Control Module (ECM),Diagnostic mode 4: Reset/erase diagnostic data.
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Generate readiness code. See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Monitors, Trips, Drive Cycles
and Readiness Codes
Checking oxygen sensor wires
- Connect test box to control module wiring harness, connect test box for wiring test.
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Check wires between test box and 4-pin connector (to control module) for open circuit according to wiring diagram.
Terminal 3 + socket 25
Terminal 4 + socket 26
Wire resistance: max: 1.5 ohms
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Also check wires for short circuit to B+ and Ground (GND).Specified value: infinite ohms