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. Driver Information Interface Warning and Information Messages*
The following messages appear only on the driver information interface. Press the  (display/information) button to see the message again with the system message indicator on. Message Condition Explanation Appears if any door or the trunk is not completely clos ...