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Check lambda probe and lambda control after catalytic converter > < Checking lambda probe and lambda control upstream of catalytic converter

A4 Mk1

Motronic Fuel Injection and Ignition System (6-cylinder)
Checking lambda control
Check lambda probe ageing of lambda probe before 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=> display group 004, display zone 3.

Test sequence

  • ‒ Connect vehicle diagnostic, testing 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 1000...2400 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, lambda probe upstream of catalytic converter (Bank 1)

Display

xxxx rpm

xxx °C

x.x s

---

Display

Engine speed

Exhaust gas temperature

Period
Lambda probe before
catalytic converter

Diagnosis status

Range

630...6800

70...850 °C

0...3.0 s

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

Specified value

1000..0,2400 rpm

Greater than 380 °C

0.1...1.8 s

B1-P1 OK

Note

If specified value is not achieved replace the lambda probe 1 upstream of catalytic converter (Bank 1)

Note on display zone 2:

Calculated value from engine speed and load.

Note on display zones 3 and 4:

The time is measured between two voltage jumps (e.g. rich- lean- rich) of the lambda probe and is thus a measure for the ageing condition of the lambda probe. If the given time is exceeded 4 = B1-S1 not OK appears in display zone.

  • ‒ Press Ckey.
 
→ When indicated on display:
Basic setting      Q
Enter display group number XXX
  • ‒ Enter "035" for "display group number 035" and confirm entry with Q key.
 
→ Display readout:
System in basic setting 35    ⇒
    1    2    3    4
  • ‒ Check specified value in display zone 4:

Note:

If the test result "OK" is shown immediately after selecting the display group the test has already been completed.

Display zones

1

2

3

4

Display group 035: Diagnosis Lambda probe ageing, lambda probe upstream of catalytic converter (Bank 2)

Display

xxxx rpm

xxx °C

x.x s

---

Display

Engine speed

Exhaust gas temperature

Period
Lambda probe before
catalytic converter

Diagnosis status

Range

630...6800

70...850 °C

0...3.0 s

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

Specified value

1000...2400 rpm

greater than 380 °C

0.1...1.8 s

B1-P1 OK

Note

If specified value is not achieved replace the lambda probe 1 upstream of catalytic converter (Bank 2)

Check lambda probe and lambda control after catalytic converter > < Checking lambda probe and lambda control upstream of catalytic converter