Our Saturn car had a light on the dash that said, "Check Engine Coolant". It was also hard to start. We took it to Sullivan-Parkhill and they charged us $99 to say that our spark plug wires, coils (2), and ignition control module were bad and needed to be replaced. They also said there was corrosion (though other mechanics said it was merely cosmetic). Lastly they said our ECM might need to be replaced. They then said they would start by replacing these three items (~$1000) with no guarantee that this would fix the problem!!!
A local shop mechanic said that these cars were notorious for a coolant temp sensor going bad (jee, isn't that what the dash was hinting at and the dealership failed to see!). He measure the sensor and replaced it - for $10 dollars!!
Imagine if some old lady or someone gullible had gone to Sullivan-Parkhill. These kind of crooks should be stopped!