EML light
My car is a 2002 Subaru Impreza 2.0 DOHC non-turbo with 105,000 miles. The EML light came on, but only downhill with throttle closed, then went out again. The fault code left behind was ‘P1507’, which I was told indicates the neutral interlock switch in the gearbox is faulty. This was replaced with a new one, but now the EML light is on all the time and the ‘P1057’ code has returned. The engine seems to start and run OK, albeit with some hesitation pulling away at junctions. Dave Leslie
The ‘P1057’ code actually indicates that there is a malfunction within the idle control system. The most likely cause of this is the idle air control valve (IAV). It is possible that the wiring or connection is at fault, but given the fact that the EML only comes on during downhill runs with the throttle closed and the light then goes go out, I would expect the problem to be a sticking IAV. I would first try removing the valve and cleaning it, but use a new gasket as a failed gasket will also cause issues. If this does not rectify the problem, I would fit a new IAV.