Yorkshire's hopes of closing the gap on LV= County Championship Division One leaders Durham were frustrated by rain at the BrightonandHoveJobs.com County Ground.
After the White Rose sent down 30 overs of generous bowling to set up a run chase against Sussex, their pursuit of a target of 300 in 64 overs ended after 20 overs following a torrential downpour.
The visitors were 81 for two when the players shook hands and their failure to force a result, allied to Durham's win over Derbyshire, means a 27.5-point deficit with two games to play.
Durham could now clinch the title by winning at home to Nottinghamshire next week. Yorkshire would have to beat both Middlesex and Surrey convincingly and hope that Durham slip up.
Skipper Andrew Gale sent in Liam Plunkett at the top of the order to try and give their chase a rousing start but he was well held by Sussex skipper Ed Joyce at midwicket in the eighth over.
And their hopes suffered another blow when Phil Jaques was trapped in front by left-arm spinner Ashar Zaidi to give the Sussex debutant a fifth wicket in the match.
Adam Lyth and Kane Williamson added 42 in 10 overs before the second cloudburst of the innings ended Yorkshire's challenge.
Earlier, Chris Nash and Rory Hamilton-Brown had both scored hundreds in a fourth-wicket stand of 260 in 30 overs as Yorkshire employed part-time bowlers to set up the declaration.
Joyce was the only wicket to fall before Sussex pulled out just before lunch when he picked out long on for 14, having completed 1,000 championship runs for the season before giving Jaques his maiden first-class wicket in his 186th match.
Hamilton-Brown's first hundred since his return to Sussex last winter followed Nash's second of the season and he finished on 126 from 83 balls with 17 fours and three sixes.
Nash made an unbeaten 167, only five runs short of a new career-best, from 137 deliveries with 26 boundaries and three sixes.