SEAT Workshop Service and Repair Manuals > Leon Mk2 > Power unit | 4 cyl. injection motor (push rods), mechanics | Mixture preparation system, electronic inj.,Gas | Testing of components | Lambda probe heating: test

Testing procedure

–	Detach the 4 contact connector -arrows- towards the Lambda probe -G39-.

–	To check the continuity of flow, attach the multimeter to contacts 1+2 from the connector to the Lambda probe, using auxiliary cables -V.A.G. 1594-.

Note!

At ambient temperature, the heating element's resistance is approx. 1...5 Ω. If the temperature rises slightly, resistance increases considerably.

If a break in probe heating is detected:

–	Replace the Lambda probe -G39-.

If the probe's heating has flow:

–	Switch the multimeter to voltage measurement and connect it to contacts 1+2 from the connector towards the control unit.

–	Start the engine and run it at idling speed. Theoretical value: 11...15 V

–	Switch off the ignition.

If there is no voltage:

–	Attach the test box -V.A.G. 1598/22- to the control unit cabling harness.

–	Using the wiring diagram, test for a break in the cable between the test box and the 4 contact connector, towards the control unit. Contact 2 + female socket 27 Cable resistance: 1.5 Ω max.

If the theoretical value is reached:

–	Test the wiring from contact 1 towards the fuel pump relay -J17-, according to the wiring diagram. → Current flow diagrams, Electrical fault finding and Fitting locations

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