Checking ageing of lambda probes -G39 and -G108 upstream of catalytic converter — AUDI

BRV
Test requirement:

Coolant temperature at least 80 °C=>Display group 004, display zone 3

Test sequence

Connect up vehicle diagnostic, testing and information system VAS 5051=>Page
01-7
and select vehicle system "01 - Engine electronics" from list. Engine must be idling.

Indicated on VAS 5051:

From list -1- select diagnostic function "04 - Basic setting".

Indicated on VAS 5051:

1 -
Enter display group

Use keypad -2- to enter "034" for "Display group number 34" and confirm by touching Q key.

Indicated on VAS 5051:

Activate basic setting by touching key -A-.

Test condition:

Engine idling

Continue with test as soon as "Test ON" appears in display zone 4.

Note:

This process may take a few minutes.

Check display in corresponding zones.

Display zones
1 · 2 · 3 · 4
Display group 034: Diagnosis of lambda probe ageing (bank 1, probe 1)
Display · xxx rpm · xxx °C · x.x s · Test ON
Significance · Engine speed · Exhaust gas temperature · Period of / lambda probe upstream of / catalytic converter · Diagnosis status
Operating range · min.: 550 rpm / max.: 7200 rpm · 70...850 °C · 0...3.0 seconds · Test OFF / Test ON / B1-P1 OK / B1-P1 not OK
Specification · 730...790 rpm · Greater than 250 °C · 0.1...1.8 s · B1-P1 OK
Note · If reading does not match specification / =>Continued onPage 24-160

Note on display zone 2:

Exhaust gas temperature displayed is a value calculated from engine speed and engine load. Temperature displayed during test must be greater than 250 °C, as otherwise test is not started or will be terminated.

Note on display zones 3 and 4:

The period indicates the time between two voltage step changes (e.g. rich - lean - rich) of the lambda probe and is thus an indication of the ageing status of the lambda probe. If the specified time is exceeded, display zone 4 shows B1-P1 n.OK.

Continuation

If reading does not match specification in display zones 3 or 4:

Replace lambda probe 1 upstream of catalytic converter -G39, bank 1 (B1-P1).
Touch ◂ key.

Indicated on VAS 5051:

1 -
Enter display group

Use keypad -2- to enter "035" for "Display group number 35" and confirm by touching Q key.

Indicated on VAS 5051:

Activate basic setting by touching key -A-.

Test condition:

Engine idling

Continue with test as soon as "Test ON" appears in display zone 4.

Note:

There may already be a diagnostic result in display zone 4 (e.g. B2-P1 OK), as certain diagnostic procedures are implemented simultaneously by the engine control unit.

Display zones
1 · 2 · 3 · 4
Display group 035: Diagnosis of lambda probe ageing (bank 2, probe 1)
Display · xxx rpm · xxx °C · x.x s · Test ON
Significance · Engine speed · Exhaust gas temperature · Period of / lambda probe upstream of / catalytic converter · Diagnosis status
Operating range · min.: 550 rpm / max.: 7200 rpm · 70...850 °C · 0...3.0 seconds · Test OFF / Test ON / B2-P1 OK / B2-P1 not OK
Specification · 730...790 rpm · Greater than 250 °C · 0.1...1.8 s · B2-P1 OK
Note · If reading does not match specification / => Continued on Page 24-163

Note on display zone 2:

Exhaust gas temperature displayed is a value calculated from engine speed and engine load. Temperature displayed during test must be greater than 250 °C, as otherwise test is not started or will be terminated.

Note on display zones 3 and 4:

The period indicates the time between two voltage step changes (e.g. rich - lean - rich) of the lambda probe and is thus an indication of the ageing status of the lambda probe. If the specified time is exceeded, display zone 4 shows B2-P1 n.OK.

Terminate function "04 - Basic setting" by touching ◂ key.

Continuation

If reading does not match specification in display zones 3 or 4:

Replace lambda probe 1 upstream of catalytic converter -G108, bank 2 (B2-P1).