Intermitten trac/stab warning, accompanyed by limp mode. Only happens at very slow speed, like coming to a stop. It never happens, say above 10mph. Would this speed condition give any clues to the cause. Sensors have been cleaned and tb cleaned last year. It won't do this when I want it to, driving to the Land Rover dealership to read the codes! Can trac/stab control cause the limp mode, or are they different causes?