Other Current Liabilities (Details 1) (USD $)
In Millions, unless otherwise specified
6 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Sep. 30, 2014
Movement in Standard Product Warranty Accrual [Roll Forward]      
Total product warranties – beginning of period $ 51 $ 57  
Accruals for product warranties 7 9  
Payments (9) (12)  
Change in estimates and other 0 3  
Total product warranties – end of period 49 57  
Less: Non-current product warranties (26) (33) (24)
Product warranties – current $ 23 $ 24 $ 27