What Type of Antifreeze & Coolant for Opel Astra. How Much Recommended antifreeze for radiators of Opel Astra. Find out how much coolant does your car need. Car A Rac presents recommended by manufacturers types for all popular vehicles. Opel Astra P0118: Engine Coolant Temp Sensor Circuit Apr 01, 2019Opel Astra P0118: Engine Coolant Temp Sensor Circuit → High Input. April 1, 2019 by Jason . P0118 is a common OBDII trouble code. It is a general code, which means that it’s going to have the same meaning for the Opel Astra as it would any other vehicle.