Checking Lambda probe ageing, Lambda probe before catalyst — VW

AVU
Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

Fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3

Check conditions

Exhaust system between catalyst and cylinder head must be free of leaks
The signals from brake light switch and brake pedal switch must be OK,
checking => Page
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.
The coolant temperature must be at least 80 °C =>Display group 100, Display zone 2
The running period must be at least 120 seconds since engine start =>Display group 100, display zone 3

Functional check

Connect fault reader V.A.G 1551 (V.A.G 1552). Start engine and select "Address word" 01 of engine control unit. When doing this the engine must be running at idling speed.
(Connecting fault reader and selecting engine control unit => Page
01-12
.)

Rapid data transfer
HELP
Select function XX
Indicated on display:

Press keys 0 and 4 for the function "Introduction of basic setting" and confirm entry with Q key.

Basic setting
Input display group number XXX
Indicated on display:

Press keys 0, 3 and 0 for the "Display group number 30" and confirm entry with Q key.

System in basic setting 30
⇒
1
2
Indicated on display:
(1...2 = Display zones)

Check Lambda control status before catalyst (display zone 1):
Specification: 1 1 1
(Significance => Page
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)
Increase engine speed to 2500...4000 rpm until the Lambda probe after catalyst is ready for use (display zone 2):
Specification: 1 1 x
(Significance => Page
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)

Notes:

The first position of the 3 digit number block fluctuates between 0 and 1 (Lambda probe heating on and off).
The rightmost position of the 3 digit number block (display zone 2) will be set to 1 only at part load and increased exhaust temperature.

If the specifications are not obtained:

Interrogate fault memory => Page
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.

If the specifications are obtained:

Press C key.
Press keys 0, 3 and 4 for "Display group number 34" and confirm entry with Q key.

System in basic setting
34
⇒
1
2
3
4
Indicated on display:
(1...4 = Display zones)

Vehicles ▸05.01

Raise engine speed to 2500...4000 rpm until display in display zone 4 jumps from "Test OFF" to "Test ON".

Vehicles 05.01 ▸

Depress brake pedal and hold.
Press accelerator pedal to wide-open position.

The engine speed is increased by the control unit to
approx. 3000 rpm.

When the diagnosis is initiated by the engine control unit the display in display zone 4 jumps from "Test OFF" to "Test ON"

Continuation for all vehicles:

Note:

This process can take a few minutes. Depending upon the control unit version, the test starts between 100...400 °C catalyst temperature (display zone 2).

Maintain the increased engine speed until the display in display zone 4 shows the result of the short test:
Specification "B1 P1 OK.

If the specification is obtained:

Press ⇒key.
Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
Switch off ignition.

If the specification is not obtained:

Carry out a road test to free Lambda probe of possible residues and repeat the test.

Observe the valid safety precautions when carrying out a road test => Page
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.

If the specifications are again not attained:

Replace Lambda probe (G39).
Erase learnt values and adapt engine control unit=> Page
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