No. At no point did u-boats actually get close to sinking the required tonnage to knock the UK out of the war and 85% of British Atlantic convoys got to the UK unmolested. The Kriegsmarine's internal memos in 1942 ordered for 1,000,000 tons of British shipping to be sunk every month. Half of that amount was only ever sunk 3 months out of the war and 600,000 only once. And these figures were based on pre-war calculations. Britain had since upped its domestic agriculture output so 1,000,000 tons probably wouldn't even be enough anymore.

Part of this may be due to a lack of attention or resources. German strategists believed that the Atlantic was of equal importance to the Mediterranian and North Africa which seems bizarre in hindsight. The Atlantic was the only was Germany could have actually knocked the UK out of the war, and this was Germany's primary objective after the Battle for France. Even the decision to attack the USSR was strategically framed as a way to bring Britain to the negotiating table (although there were obviously other considerations). And the Atlantic theatre was considered the most important by British military personnel. The Mediterranian was important but it wasn't crucial to Britain and the German fixation on it was a strategic mistake. Resources were sucked into the Eastern Front and production of aircraft which attacked British convoys was lacklustre, only enough aircraft were produced to replace losses and Messerschmidt seemed more fixated on creating new aircraft designs (having 40 in testing) than upping production or continuously improving a few designs. Germany also lacked airspace to train new pilots unlike Britain who trained pilots in Africa and Canada where they were safe. Germany also lacked pilots and the Luftwaffe was being stretched over 4 fronts.

Memos and official material was constantly published calling for increased attention to u-boats, and for more tonnage to be sank but with the Eastern Front sucking in resources very little was done to make good on any of these pledges.

Source: James Holland - The War in the West 1941-43