Golf III L4-2.0L (ABA) (1995)
Control Checking - Heated Oxygen Sensor
HEATED OXYGEN SENSOR (HO2S) AND OXYGEN SENSOR CONTROL, CHECKING.
Test using VAG 1551 Scan Tool (ST) with engine idling.
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Engine basic setting OK
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Exhaust system not leaking between Three Way Catalytic converter (TWC) and cylinder head.
Voltage Supply for Heated Oxygen sensor heater circuit OK => Repair Group 01, Output Diagnostic Test Mode.
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VAG 1551 Scan Tool connected. Go to "Read Measuring Value Block" function (08) display group 01 => Repair group 01.
Indicated on display (1-4 = display fields)
Continue testing only when:
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Engine Coolant Temperature is over 80°C (176°F - channel 2)
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Engine has run 2 minutes at idle
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Read Oxygen Sensor factor in channel 3.
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Value displayed fluctuates up and down If value in channel 3 does not fluctuate:
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Insure that HO2S heater is functioning properly.
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Briefly raise engine speed above 2000 rpm and repeat test.
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Press buttons -0- and -6- to select Function "End Output".
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Press -0- to confirm input.
If Oxygen Sensor display 1.00 does not change even during acceleration:
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Disconnect harness connector from Engine Coolant Temperature Sensor.
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Press buttons -0- and -5- to select Function "Erase DTC Memory".
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Press -Q- to confirm input.
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Unplug Heated Oxygen sensor harness connector.
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Connect adapter lead from VW 1594 to cavity 4 (wiring to Motronic Engine Control Module J220) and hold to Ground (GND).