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. Using Automatic Climate Control
The automatic climate control system maintains the interior temperature you select. The system also selects the proper mix of heated or cooled air that raises or lowers the interior temperature to your preference as quickly as possible. Use the system when the engine is running. 1. P ...