Golf III L4-1984cc 2.0L SOHC (1993)
Oxygen Sensor: Testing and Inspection
With VAG
CHECKING OXYGEN SENSOR AND OXYGEN SENSOR CONTROL
NOTE: Test using VAG 1551 Scan Tool (ST) with engine idling.
REQUIREMENTS
^
Engine basic setting OK.
^
Exhaust system not leaking between Three Way Catalytic Converter (TWC) and cylinder head.
^
Voltage supply for Heated Oxygen Sensor (HO2S) heater circuit OK.
^
VAG 1551 Scan Tool connected with "Read Measuring Value Block" function (08) selected (display group number 1).
PROCEDURE
^
Indicated on display (1 - 4 = display fields)
Read measuring value block 1
-->
1 2 3 4
-
Continue testing only when:
^
Engine Coolant Temperature (ECT) is over 80°C (176°F) - display field 2.
^
Engine has run 2 minutes at idle.
-
Read Oxygen Sensor factor in display field 3.
^
Specified value: display fluctuates.
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If value in display field 3 does not fluctuate:
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Briefly accelerate and repeat test.
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Press --> button.
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Press buttons -0- and -6- to select the "End Output" function.
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Press -Q- to confirm input.
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If Oxygen Sensor factor 1.00 does not change even during acceleration:
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Disconnect connector -1- from Engine Coolant Temperature Sensor -2-.
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Press buttons -0- and -5- to select the "Erase DTC Memory" function.
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Press -Q- to confirm input.
