Take the appropriate action and verify that the warning light turns off.

Taking Action
Message Indicated on DisplayMazda 6 Owners Manual: Exterior lighting system
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Mazda 6 Owners Manual: Refrigerant pressure switch inspection
1. Install the SST (gas charging set).
2. Disconnect the refrigerant pressure switch connector.
3. Verify the high-pressure side reading of the SST (manifold gauge)
and continuity between the terminals of the refrigerant pressure switch.
If not as specified, replace the refrigerant pressure ...