The Briton will leave McLaren after the final race in Sao Paulo and has yet to secure a drive for 2005.
Coulthard vowed to race on, even if it means sitting out a year, however.
"I'm not ready to retire," he told Reuters. "I'll try and get a drive for next year and if I don't then I'll try and get one the following year."
Coulthard has struggled for McLaren again this season and he was forced out of Sunday's Japanese Grand Prix after a collision with Ferrari's Rubens Barrichello.
"It was disappointing, but the whole last two years have been disappointing," shrugged Coulthard, a winner of 13 Formula One races. "You just have to accept it."
Coulthard has been linked with a move to BAR if Jenson Button's defection to Williams is approved by the sport's contract recognition board, which meets in Milan on Friday.
"I think I have the pace, the desire, the commitment and the overtaking ability to be competitive," said Coulthard, whose last victory came in Melbourne at the start of the 2003 season.
"But until I sign a contract for next season I've got nothing. It's as simple as that. I hope Brazil won't be my last Grand Prix.
"I'll do what I can to make sure I'm on the grid for next season."
Coulthard was comprehensively outperformed by Finnish team mate Kimi Raikkonen in 2003.
The 33-year-old, who has been with McLaren since 1996, complained of a lack of support within the team this season.
"The only thing that stands between me performing at the highest level is just being in a team where you've got the support -- you know they want you to be there," he said.
"I'm not saying the team's against me but naturally their resources go into where they're investing for the future."
