skoda Workshop Repair Guides

Skoda Workshop Service and Repair Manuals

ABOUT US
Testing catalyst efficiency > < Testing lambda probe and lambda control upstream of catalytic converter

Fabia Mk1

Testing lambda probe and lambda control after catalyst
Testing lambda probe and lambda control after catalyst
Special tools and workshop equipment required
t  Vehicle system tester -V.A.G 1552 -
t  Diagnostic cable -V.A.G 1551/3, 3A, 3B, 3C-
t  Hand multimeter (e.g. -V.A.G 1526 A-)
t  Adapter cable set (e.g. -V.A.G 1594 A-)
Test conditions
l  The fuel pump relay must be OK.
   
l  Fuse 9 must be OK.
l  Coolant temperature minimum 80°C
l  No leaks in exhaust system between catalytic converter and cylinder head
Check for proper operation
–  Check display groups 030, 036, 037, 041 and 043 → Chapter or generate readiness code → Chapter.
If the specified value is not reached:
–  Perform a test drive to clear the lambda probe of possible residual values and repeat the test.
If the specification is also not shown in the display field after a test drive:
Testing heater
–  Disconnect the 4-pin plug connection to the lambda probe downstream of catalytic converter -G130-.
  S01-0094
–  Perform a continuity test (resistance measurement) between the contacts of the plug at the lambda probe with the handheld multimeter according to the current flow diagram → Current flow diagrams and Fitting locations.
  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 -G130- if an open circuit is detected.
If there is continuity in the heating element, check the power supply for lambda probe heater -Z19- → Current flow diagrams and Fitting locations.
Test basic voltage
–  Disconnect the 4-pin plug connection to the lambda probe downstream of catalytic converter -G130-.
  S24-0408
–  Connect the handheld multimeter, for voltage measurement, to the contacts of the plug on the wiring loom according to the current flow diagram → Current flow diagrams and Fitting locations.
–  Leave engine on and measure the supply voltage.
Specified value: 0.400 up to 0.500 V
–  Switch off ignition.
If the specified value is not reached:
–  Check lambda probe wire downstream of catalytic converter → Current flow diagrams and Fitting locations.
If the specified value is reached:
–  Replace lambda probe downstream of catalytic converter -G130- → 1.4/55; 1.4/59; 1.4/74 Engine - Mechanics → Rep. Gr.26.
  S24-0408

Testing catalyst efficiency > < Testing lambda probe and lambda control upstream of catalytic converter