Coolant temperature red light flashing
 

I have a 91 passat 1,8. The last few days my coolant temp light is flashing,
sometimes when I'm driving. I've checked everything, and all seems to be fine.
Is it the sensor that needs replacing and which one is it on the motor, thanks, Mcjensen

Have you checked the coolant level??

Yes coolant levels are fine, engine isn't too hot,
so I'm thinking its a coolant sensor.
Any ideas how many and or where there sensors are?