[disfin]

Troy is right. Check the back of your steering wheel and make sure the cancelling tab is still in place. Then look at your turn signal switch itself and simulate the cancelling process. First, engage the turn signal by moving it up or down until it clicks into place. Then push the white cancelling tab up or down. The lever should return to the middle position just as in normal operation.

Just take it apart. You know you want to....