electronic ignition module on 2007 Jeep Grand Cherokee

My jeep wouldn't start. Had it looked at by dealership and they said it could be electronic ignition module. They recommended it be replaced. $900 to fix. I had it back and 5 days later the same thing happened. Now they say it is corrosion of the wires. should they have seen this before they replaced module?

Asked by for the 2007 Jeep Grand Cherokee
sounds logical. did you ask them that at the dealer??
how did it run for the 5 days??