codes u0401/p0303 engine light comes on ramdemly on 2007 BMW 328i

changed coil pack on cyl 3 too cyl 2 failed then changed spaked plugs failed

by in Youngstown, NY on December 29, 2013
1 answer
ANSWER by , December 29, 2013
Cannot verify the U0401 code, but a 'U' code is normally a no communication on the Can lines between the modules.