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Lambda probe heater Check -Z19 for lambda probe upstream of catalytic converter > < Checking Lambda probe and Lambda control before catalytic converter

A4 Mk1

Motronic Fuel Injection and Ignition System (4-cyl) Turbo
Checking lambda control
Check lambda probe ageing upstream of catalytic converter
 
W00-0437

Special tools and workshop equipment required

  • ◆ → V.A.G 1788/10 speedometer
 
W00-0706
  • ◆ VAS 5051 with VAS 5051/1

or

  • ◆ V.A.G 1551 with V.A.G 1551/3 A

Test requirements:

  • ● Coolant temperature at least 80 °C.

Test sequence

  • ‒ Connect up vehicle diagnosis, measurement and information system VAS 5051 or fault reader V.A.G 1551 and select engine electronics control unit with "Address word" 01 .
    For this purpose, the engine must be running at idle speed.
 
→ When adjacent display appears:
Rapid data transfer    HELP
Select function XX
  • ‒ Enter "04" to select "Start basic setting" and confirm with Q key.
 
→ When indicated on display:
Basic setting     Q
Enter display group number XXX
  • ‒ Enter "034" for "display group number 034" and confirm entry with Q key.
 
→ Display readout:
System in basic setting 34    ⇒
    1    2    3    4
  • ‒ Set engine speed to 2300...0.2800 rpm using engine speed controller V.A.G 1788/10.
  • ‒ Check specified value in display zone 4:

Note:

This process can take a few minutes.

Display zones

1

2

3

4

Display group 034: Diagnosis lambda probe ageing

Display

xxxx rpm

xxx °C

x.x

---

Display

Engine speed

Exhaust gas temperature

Dynamics factor

Diagnosis status

Range

Test OFF
Test ON
B1-P1 OK
B1-P1 not OK

Specified value

2300...2800 rpm

greater than 350 °C

0.5...2.5

B1-P1 OK

Note:

If specified value is not attained
=> ContinuePage 24-89

Note on display zone 2:

Calculated value from engine speed and load.

Note on display zones 3 and 4:

The dynamics factor is the characteristic for the ageing of the lambda probe. The lower the dynamics factor the more advanced is the ageing of the lambda probe.

(cont.)

If specified value in display zone 3 or 4 is not attained:

  • ‒ Perform test drive to free Lambda from any possible residues and repeat the test.

If specified value in display zone 3 or 4 is not attained, even after a test drive has been performed:

  • ‒ Replace the lambda probe 1 upstream of catalytic converter -G39.

Lambda probe heater Check -Z19 for lambda probe upstream of catalytic converter > < Checking Lambda probe and Lambda control before catalytic converter