I have had a 407 for a year and enjoyed the driving experience. Apart from the cost if the fuel. 2.2 se luxury pack. The MOT is due and i cannot turn the abs/esp light off. Have replaced 3 of the 4 sensors, but light remains on. Diagnostic says rear sensor fault (not planet) spark says checked the wiring and all in tact, says thinks the abs ecu is corrupted. Inspected pins no sign if corrosion........ Any ideas.