my car show de oil pressure light y shut off and do not start is a saturn

...I'm going to suspect an undervoltage condition at the instrument panel...because the main ground is corroded....the 1/0 black cable that comes from the battery and with a lug connects to the rest of the car providing grounding for the startermotor and the delicate components such as the fuel pressure, ignition and the ECU...so wirebrush this critical connection...get a brand new battery and you will be okay then~

the stuck ignition relay will also be keen to operate of of 12.5 volts rather then "brown" power with varying voltages and available amps~

I'm sure this has been figured out by Sergio by now seeing this was posted back in January of 2014, but to let anyone else that might come along reading this know, if the engine control module (ECM) senses a sudden loss of oil pressure (from lack of oil) it will turn off the engine so no damage will be caused to the engine by the lack of lubrication.