crank position sensor location

[corvairbob]

i have a 06 2.2 auto that i think i need to change the cps. i had to replace the ecu and now i get a code p0315 every now and then. some say the cps may be failing. but i get conflicting answers on the location. some say by the crank pulley and some say behind the starter.

also can i just change this sensor without having to relearn the ech? conflicting answers on this as well.