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. Accessory Power Socket
The accessory power socket can be used when the ignition switch is in ACCESSORY or ON *1. Open the cover to use it. NOTICE Do not insert an automotive type cigarette lighter element: The power socket can overheat. The accessory power socket is designed to supply power for 12 volt D ...