Security light comes ON when often the weather is warm!! What can be the problem

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I have a '98 Riviera with only 75000 miles and is a great car! But when the spring is coming and outside is hot I'm getting angry (because of my car VATS system). The Security light stays ON, I have to wait 3 min to try again. The engine starts. I have no problem with fuel pump, radio, panel lights...everything works well. Sometimes I have to try twice(3 min rest). This week I had a rest 3 min near a gas_station's pump which is not funny. I suppose that there is a problem with the key contact inside of ignition_cylinder or with the reading of the value (ohm) on the key's chip. Also I'm looking about how to bypass this system. Here we don't have any GM dealer or GM auto_service. I'm trying to solve that on my own or to give an advice to my mechanic what to do. I'm sure nobody will try to still this car (In this part of Europe is very rare and only a few people love old american cars). Help please!