seat Workshop Repair Guides

SEAT Workshop Service and Repair Manuals

ABOUT US
Lambda probe heating after catalytic converter checking > < Checking components

Leon Mk2

Lambda probe heating before catalytic converter checking
Lambda probe heating before catalytic converter checking
Special tools and workshop equipment required
t  Fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552- with cable -V.A.G 1551/3B-
t  Test box -V.A.G 1598/31-
t  Hand multimeter -V.A.G 1526 A- or multimeter -V.A.G 1715-
t  Adapter set -V.A.G 1594 C-
t  Current flow diagram
Check conditions
   
l  Fuses no. 15 and 18, OK
l  Battery voltage at least 11.5 V
l  Fuel pump relay must be OK
Test sequence
–  Connect fault reader -V.A.G 1551/V.A.G 1552-. Start engine and enter “Address code” 01 to select engine control unit. (Fault reader: Connecting and selecting the engine control unit → Chapter).
  E01-0119
Indicated on display:
–  Press keys 0 and 8 for the function “Read measured value block” and confirm entry with Q -key.
  
Rapid data transfer                 HELP
Select function XX
Indicated on display:
–  Press keys 0, 4 and 1 for “Display group number 41” and confirm entry with Q -key.
  
Read measured value block           HELP
Input display group number XXX
Indicated on display: (1...4 = Display fields)
–  Check the status of the Lambda probe heating before catalytic converter in display field 2:
   Display: Htg. bC. ON
  Note!
Lambda probe heating is switched on and off depending on engine load, so the reading in display field 2 can be Htg. bC. ON or alternate between Htg. bC ON and Htg. bC OFF.
If the specification is not obtained:
  
Read measured value block          41 ->
         1         2         3         4
–  Unplug 6-pin connector (black) to Lambda probe before catalytic converter -G39--arrow-.
  E24-0028
–  Check probe heating for continuity at Lambda probe connector contacts 1 and 2.
If it is determined that probe heating has an open circuit:
–  Replace the Lambda probe before catalytic converter -G39-.
If probe heating has continuity:
Checking voltage supply
  E24-0072
–  Switch multimeter to voltage test and connect it to contacts 1+2 of connector to engine control unit with aux. cables from -V.A.G 1594 C-.
–  Start engine and run at idling speed.
–  Measure voltage supply and observe display group 41, display field 2.
Display Htg. bC. ON
   Specification: 11.0...14.5 V
Reading Htg. bC. ON/Htg. bC. OFF (alternating):
   Specification: oscillates between 0.0...12.0 V
–  Press → -key.
–  Press keys 0 and 6 for the “End output” function and confirm input with the Q -key.
–  Switch off ignition.
If no voltage is present:
  M24-0056
–  Connect test box -V.A.G 1598/31- to control unit wiring harness. The engine control unit remains disconnected.
–  Check wiring between test box and 6-pin connector (to control unit) for open circuit according to current flow diagram.
   Contact 1+socket 5
   Wire resistance: max. 1.5 Ω
If the specification is obtained:
  N24-0943
–  Check wiring from contact 2 to fuel pump relay -J17- according to current flow diagram → Current flow diagrams, Electrical fault finding and Fitting locations.
  M24-0056

Lambda probe heating after catalytic converter checking > < Checking components