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Testing lambda probe G130 and lambda control downstream of catalytic converter > < Lambda control

Fabia Mk1

Testing lambda probeG39 and lambda control upstream of catalytic converter
Testing lambda probe -G39- and lambda control upstream of catalytic converter
Special tools and workshop equipment required
t  Vehicle system tester -V.A.G 1552- with cable -V.A.G 1551/3, 3A, 3B, 3C-
t  Hand multimeter (e.g. -V.A.G 1715-)
t  Adapter cable set (e.g. -V.A.G 1594 A, B, C-)
Test conditions
l  Fuel pump relay o.k., test → Chapter, actuator diagnosis
   
l  Fuse no. 9 o.k.
l  Coolant temperature must be at least 80 °C
l  No leaks in exhaust system between catalytic converter and cylinder head
Test sequence
For engine with engine identification characters AWY, BMD, BME
Check the function of lambda probe upstream of the catalytic converter -G39- and the lamda control function “Reading measured value block”, check indicator groups 030 and 033 → Chapter.
If the specified values are not reached:
–  Switch off ignition.
  S01-0094
–  Disconnect the 4-pin plug connector from the lambda probe -G39--arrow-.
–  Measure the resistance using a hand-held multimeter between contacts 1 + 2 of the plug connection -1-.
  Note
At ambient temperature (approx. 20 °C) the heating element resistance is of approx. 1 to 5 Ω. The resistance increases considerably even if the temperature rises only slightly.
Replace the lambda probe -G39- if an open circuit is detected.
–  Check the supply voltage or lines to the lambda probe heating -Z19- according to the current diagram.
If the resistance and the supply voltage are o.k.:
  S24-0500
–  Connect handheld multimeter for voltage measurement to contacts 3 + 4 of plug connector -2-.
–  Start-up the engine and measure the voltage.
t  Specified value: 0.40...0.50 V
–  Switch off ignition.
If the specified value is reached:
–  Replace lambda probe -G39- → 1.2/40; 1.2/47 Engine - Mechanics → Rep. Gr.26.
If the specified value is not reached:
–  Test wiring and plug connections according to current flow diagram.
If no fault was found:
–  Replace engine control unit → Chapter.
For engine with engine identification characters AZQ
Check the function of the lambda probe upstream of catalytic converter -G39- and the lamda control by using the function “Reading measured value block”, check display groups 030, 033 and 041 → Chapter.
If the specified values are not reached:
–  Switch off ignition.
–  Separate 6-pin plug connection to lambda probe -G39-.
  S24-0500
–  Measure the resistance using a hand-held multimeter between contacts 3 and 4 of the plug connection -1-.
  Note
At ambient temperature (approx. 20 °C) the heating element resistance is of approx. 1 to 5 Ω. The resistance increases considerably even if the temperature rises only slightly.
Replace the lambda probe -G39- if an open circuit is detected.
–  Check the supply voltage or lines to the lambda probe heating -Z19- according to the current diagram.
If the resistance and the supply voltage are o.k.:
  S24-0531
–  Connect handheld multimeter for voltage measurement to contacts 1 + 5 of plug connector -2-.
–  Leave engine on and measure the supply voltage.
t  Specified value: 0.40...0.50 V
–  Switch off ignition.
If the specified value is reached:
–  Replace lambda probe -G39- → 1.2/40; 1.2/47 Engine - Mechanics → Rep. Gr.26.
If the specified value is not reached:
–  Test wiring and plug connections according to current flow diagram.
If no fault was found:
–  Replace engine control unit → Chapter.
  S24-0531

Testing lambda probe G130 and lambda control downstream of catalytic converter > < Lambda control