skoda Workshop Repair Guides

Skoda Workshop Service and Repair Manuals

ABOUT US
Test of ageing of lambda probe upstream of catalytic converter G39 > < Testing lambda probe G39 and lambda control upstream of catalytic converter

Fabia Mk1

Testing lambda probeG130 and lambda control downstream of catalytic converter
Testing lambda probe -G130 - and lambda control downstream of catalytic converter
  Note
There is only one lamda control but it uses two lamda probes whereby the lamda control after the catalytic converter is for the so-called “trim control” (improvement control) and serves for diagnostic purposes. It takes priority over the lambda control upstream of the 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
Check the function of the lambda probe -G130- and the lambda control by using the function “Reading measured value block”, check display groups 030 and 043 → Chapter.
If the specified values are not reached:
–  Switch off ignition.
  S01-0094
–  Disconnect the 4-pin plug connector from the lambda probe -G130--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.
If there is an interruption, replace the lambda probe after catalyst -G130-.
–  Check the supply voltage or lines to the lambda probe heating downstream of the catalytic converter -Z29- according to the current diagram.
If the resistance and the supply voltage are o.k.:
  S24-0501
–  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 downstream of catalytic converter -G130- → 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.
  S24-0501

Test of ageing of lambda probe upstream of catalytic converter G39 > < Testing lambda probe G39 and lambda control upstream of catalytic converter