on March 17, 2011, 11:26 pm, in reply to "Seat Leon - MOT Emission Failure + EML Illuminated"
I have not got all the info with me at the moment but I recently tested a Golf with a 1.4 AXP. From memory the wires from the sensor change colour at the multi plug. I seem to remember that the heater is the same as a zirconia type ie: 12V and are the white and grey wires. The ref voltage (nernst cell?) was about 2.5v at the black wire. I think the pump is fed by the red and yellow wires but these change polarity depending on which direction the pump is working in order to stabilise the ref voltage (easily checked with a scope).
Hope I got that right but someone will probably correct it if I'm wrong.
Regards, Bryan.
