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Testing lambda probe and lambda control (after catalytic converter) - engine code ANB > < Testing lambda probe and lambda control (before catalytic converter)

A4 Mk1

Motronic injection and ignition system (4-cyl. turbo)
Testing lambda control
Testing lambda probe (before catalytic converter) for ageing - engine code ANB
 
W00-0437

Special tools and workshop equipment required

  • ◆ → V.A.G 1788/10 Engine speed adjuster
 
W00-0706
  • ◆ VAS 5051 and VAS 5051/1

or

  • ◆ V.A.G 1551 and V.A.G 1551/3 A

Test requirement:

  • ● Coolant temperature at least 80 °C =>Display group 004, Display zone 3.

Test sequence

  • ‒ Connect vehicle diagnostic, testing and information system VAS 5051 (or fault reader V.A.G 1551). Select engine electronics control unit by entering the address word "01" ; when doing this the engine must be running at idling speed.
 
→ Indicated on display:
Rapid data transfer     HELP
Select function XX
  • ‒ Enter "04" to select "Basic setting" and confirm with Q key.
 
→ Indicated on display:
Introduction of basic setting    Q
Enter display group number XXX
  • ‒ Enter "034" for Display Group 034 and confirm entry with Q key.
 
→ Indicated on display:
System in basic setting 34    ⇒
    1    2    3    4
  • ‒ Set engine speed at between 1800 and 2200 rpm using the speed regulator V.A.G 1788/10.
  • ‒ Continue the test as soon as "Test ON" appears in display zone 4.

Note:

This process can take a few minutes.

Display zones

1

2

3

4

Display group 034: Diagnosis of lambda probe ageing

Display

xxxx rpm

xxx °C

x.x s

---

Indicates

Engine speed

Exhaust temperature

Cycle duration of
lambda probe (before catalytic converter)

Status of diagnosis

Range

0...6800

70...850 °C

0...3.0 s

Test OFF
Test ON
B1-P1 O.K.
B1-P1 n. O.K.

Specification

1800...2200 rpm

Higher than 350 °C

0.0...1.0 s

B1-P1 O.K.

Note

If specification is not attained, refer to
Page 24-88

Note on display zone 2:

Value calculated from engine speed and engine load.

Note on display zones 3 and 4:

The cycle duration of the lambda probe indicates the time between two voltage pulses (e.g. rich - lean - rich). It is therefore a means of evaluating lambda probe ageing (i.e. the condition of the lambda probe). If the indicated cycle duration is exceeded, "B1-P1 n. OK" will appear in display zone 4.

Further notes

If the readout in display zone 3 or 4 does not match the specification:

  • ‒ Take car for a test drive to free lambda probe of any deposits, then repeat the test.

If the readout in display zone 3 or 4 still does not match the specification even after the test drive:

  • ‒ Replace the lambda probe 1 (before catalytic converter) -G39.

Testing lambda probe and lambda control (after catalytic converter) - engine code ANB > < Testing lambda probe and lambda control (before catalytic converter)