Pioneer AVIC-505 Owner's Manual page 136

• If you enter or exit a multi-story car park lot or similar with a spiral junction
• If your vehicle is turned on a turntable or similar
• If your vehicle's wheels spin, such as on a rough track or in snow
• If you put on chains, or change your tyres for some of a different size
• If trees or other obstacles block the GPS signals for a considerable period