Yes it's easy to do.
You need a 5 pin relay but you'll only need to use 4 pins of it. These are numbered 30 85 86 87a. The 87 pin won't be connected.
Pin 30 and 87a need to be connected to one of the coolant sensor wires. The wire needs cutting and joining to these two pins.
The 85 pin goes to a ground connection.
Pin 86 needs to be joined into the starter trigger wire (thin wire)
This will then disconnect the the coolant sensor when the engine is cranking but reconnect it when the starter is released.
You can Google 5 pin relay for an idea of what it is.