Honda Civic Service Manual: Engine Cooling

Engine

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Coolant Replacement (R18A9)

1. Radiator Cap 1. Wait until the engine is cool, then carefully remove the radiator cap. ...

See also:

Honda Civic Owners Manual. Tire Pressure Monitoring System (TPMS)
U.S. models Instead of directly measuring the pressure in each tire, the TPMS on this vehicle monitors and compares the rolling radius and rotational characteristics of each wheel and tire while you are driving to determine if one or more tires are significantly under-inflated. This will cause ...