Not sure what you mean by exterior light warning, but perhaps you have a burned out bulb which is crying out for attention.

The tire pressure light requires that you set all tires to the desired pressure, then go through a reset procedure by pressing in the button on the dash with the flat tire symbol (usually in the centre stack, below the HVAC controls). You may not have a problem with the light, but rather with a low tire pressure.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue