Why does my 2002 Pontaic GrandAm starts in cold weather but not hot?

The dash caution lites are all out when the key is turned to acc or start and the car doesnt start but turn signals, windows, headlites, horn, and raddio works. But everything seems to operate when the weather is cooler.

A quick guess is that the ect sensor (engine coolant temperature) is lying to the engine computer. It’s a cheap part…and easy to change.

Does the engine crank? Is the engine warm when the problem occurs? Does it only happen with a cold engine? The other posters may want to know.

The dash caution lites are all out when the key is turned to acc or start

Do you mean they don’t come on at all?