Net Property (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Sep. 30, 2014
Property, Plant and Equipment [Line Items]
Property at cost	$ 1,297	$ 1,397
Less accumulated depreciation	(910)	(973)
Net property	387	424
Land and land improvements
Property, Plant and Equipment [Line Items]
Property at cost	32	34
Buildings
Property, Plant and Equipment [Line Items]
Property at cost	219	236
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property at cost	860	906
Company-owned tooling
Property, Plant and Equipment [Line Items]
Property at cost	137	155
Construction in progress
Property, Plant and Equipment [Line Items]
Property at cost	$ 49	$ 66