Code po340 in a 2000 toyota camry?

yesterday while driving and my 2000 toyota camry just shut off on me and my dad did a diagnostic coding on it a found a the code po340 and it the camshaft position sensor malfunction and this car is a 4cly and never had this problem before and the timing belt was changed in 2007 and the miles was at 75,000 and now the mile are at 155,000 mile. i try to start the car and it wants to turn over but wont start can some one help me please