I've had this problem for some time so I rigged an LED inside the car and connected it to various terminals on relay T9. When the engine cut out the supply side of the relay was OK but the earth side of the coil was loosing its connection to earth in the ECU(M10). I am tempted to connect the earth side of the coil direct to earth but I cannot find out what functions I would be bypassing in the ECU. Does anyone know? I have checked all earths and even run a wire from the ECU direct to the battery earth. The MIL does not come on and there are no fault codes registered. Strangely the engine always restarts after turning the ignition off and on again.