The TV ad, created by agency adam&eveDDB, showed various scenarios in which the AA was required by motorists, with a voiceover stating: "With more patrols, more specialist skills and more expertise than anyone else, we are the Automobile Association. We are the AA."
AA competitor RAC, and a member of the public, questioned whether the "more than anyone else" claims were misleading in a complaint to the ASA.
The ASA has upheld the complaints and ruled that the ads "must not appear again in their current form".
Edmund King, AA president, said he was "surprised" by the decision, but added: "We’re a bit busy getting people back on the road to comment further."
An RAC spokesman said: "The breakdown sector is a very competitive one, which makes it all the more important that every business communicates clearly and accurately with consumers, especially where large-scale advertising campaigns are concerned.
"We therefore believe that the ASA’s final ruling upholding this complaint is significant in that it ensures that motorists’ purchasing decisions will not be adversely affected by misleading and unsubstantiated claims."
ASA rulings are released every Wednesday.