# Oxygen Sensor VAG-COM Test



## audibahamas (May 29, 2009)

Can anyone give some insight on a possible way to test the Oxygen sensors using VAG-COM?


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## sabikeuk (Dec 2, 2008)

Below are tests you which includes testing of oxygen sensor, you should start with point 2.8.3 - in total 10 tests

2.8.3 Block 030 - Lambda Control Operating Status
Note! Before continuing:
• Adjust the engine RPM to 2000 using the handy tool, or your steady leg
Enter the Basic Settings block 030.

In block 030, the fields 1 and 2 are three-digit binary codes that give the status of
the oxygen sensors. The first digit indicates the probe heating status, the second
digit indicates the probe condition, and the third digit indicates lambda control
status. The value should fluctuate between 111 (heater on) and 011 (heater off).
The last two digits can also fluctuate between 1 and 0, but should be
predominantly 11.
Do not continue with testing until the displays have reached 111 in field 1 and
110 in field 2, at least once.

2.8.4 Block 034 - Ageing of Pre-Cat Oxygen Sensor
Enter the Basic Settings block 034.
Field 2 shows the Exhaus Gas Temperature, measured by the oxygen sensor. It
must be above 350°C for the test to succeed.
The value in field 3 is called "dynamic factor". It is an indicator for lambda probe
ageing. The value should be above 0.5; the value for a new sensor is ~2.0. It will
decrease as the sensor ages.
The field 4 will say either 'TEST OFF/ON' before/while the test is running, and
either 'B1-S1 OK' or 'B1-S1 NOT OK' afterwards. It may take several minutes to
obtain result of diagnosis.
Do not continue with testing unless the field 4 is indicating "B1-S1 OK".
2.8.5 Block 036 - Post-Cat Oxygen Sensor Diagnosis
Enter the Basic Settings block 036.
The field 2 will say either 'TEST OFF/ON' before/while the test is running, and
either 'B1-S2 OK' or 'B1-S2 NOT OK' afterwards. It may take several minutes to
obtain result of diagnosis.
Do not continue with testing unless the field 2 is indicating "B1-S2 OK".
2.8.6 Block 037 - Lambda System Diagnosis
Enter the Basic Settings block 037.
The value in field 2 is the post-cat lambda probe output voltage, with range of
0.10 &#8230; 0.95V. It should remain as constant as possible. Considerable voltage
fluctuations are an indication of catalytic converter damage. A constant voltage of
0.450V is an indication of damaged wiring.
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The third field is lambda correction value between the pre and post-cat sensors.
It should stay below 0.02.
Note. If the lambda probe voltage is OK and the lambda correction value is still
greater than 0.02, even after a test drive, this is an indication of ageing of the
lambda probe upstream of the catalytic converter.
The field 4 will say either 'TEST OFF/ON' before/while the test is running, and
either 'System OK' or 'System NOT OK' afterwards. It may take several minutes
to obtain result of diagnosis.
Do not continue with testing unless the field 4 is indicating "System OK".
2.8.7 Block 043 - Ageing of Post-Cat Oxygen Sensor
Enter the Basic Settings block 043.
The field 4 will say either 'TEST OFF/ON' before/while the test is running, and
either 'B1-S2 OK' or 'B1-S2 NOT OK' afterwards. It may take several minutes to
obtain result of diagnosis.
Do not continue with testing unless the field 4 is indicating "B1-S2 OK".
2.8.8 Block 046 - Catalytic Converter Diagnosis
Enter the Basic Settings block 046.
Field 2 indicates the CAT Temperature (EGT), which must be more than 320°C
for the test to start. Increase engine speed if necessary.
Field 3 is the CAT Conversion Efficiency. If the cat is good, the value should be
below 0.50 at the end of the test.
The field 4 will say either 'TEST OFF/ON' before/while the test is running, and
either 'CAT B1 OK' or 'CAT B1 NOT OK' afterwards.
Do not continue with testing unless the field 4 is indicating "CAT B1 OK".
2.8.9 Block 070 - Fuel Tank Breather Valve Diagnosis
Note! Before continuing:
• Remove the accelerator tool / leg - let the engine idle
Enter the Basic Settings block 070.
Note. If the test does not start or if the display switches from "Test ON" to "Test
OFF" instantly, give a brief burst of throttle and the test will be repeated.
The field 4 will say either 'TEST OFF/ON' before/while the test is running, and
either 'TBV OK' or 'TBV NOT OK' afterwards.
Do not continue with testing unless the field 4 is indicating "TBV OK".
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2.8.10 Block 056 - Idling Speed Diagnosis
Enter the Basic Settings block 056.
Field 1 indicates the actual engine speed. Field 2 indicates the requested speed,
which is usually 760rpm, unless changed in the engine adaptation. The value can
be higher also during warmup.
Verify that the actual speed coincides with the requested speed. Turn on Air
Conditioning. After short fluctuation, the values should coincide again.
Exit the Basic Settings screen.
2.8.11 Readiness
Enter the Readiness function "15".
All the fields should indicate "PASSED".


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