Six-step　commutation　control　widely　used　in　brushless　DC　(BLDC)　motor　can　be　applied　to　consequent　pole　permanent　magnet　(CPPM)　belt　starter　generator　(BSG)　with　trapezoidal　back　electromotive　force　(EMF)　in　the　starter　state.　However,　rotor　position　detection　with　three　Hall　sensors　in　BLDC　motor　can　hardly　be　employed　in　CPPM　BSG　due　to　asymmetric　flux　distribution　in　each　pole　side　of　CPPM　BSG.　This　paper　presents　a　low-cost　rotor　position　detection　method　for　CPPM　BSG　in　which　six　Hall　sensors　are　proposed　to　be　used　based　on　the　analysis　of　flux　distribution　by　3D　FEA.　In　the　method,　the　six　Hall　sensors　are　divided　into　three　groups　and　two　signals　in　each　group　are　combined　through　performing　logic　operations.　In　addition,　offset　angle　between　back　EMF　and　the　related　Hall　signal　can　be　compensated　by　moving　the　Hall　sensors.　Experiments　of　a　2　kW　CPPM　BSG　prototype　have　also　been　performed　to　verify　the　proposed　method.