1999 Honda Civic 1999 honda hard to start when engin hot

1999 honda civic check engine light on,and scaned the codes,codes number is p0118 engine coolant temperature circuit high input.when engine is hot it will hard to start , when engine cool down it will start well , the engine idle speed will above 1000rpm, so shall i replace the coolant temperature sensor?or the other components failed,any ideas ? please help me.