I have 09 Pontiac g6 3.5l vin N and have had my crankshaft position sensor replaced 2 times in 3 years. Always get p0315 code. Recently it threw a throttle position sensor fault but after removing and reinstalling plug that never happened again. Some mechanics say it needs scan tool to relearn some day it doesn't. I have had it relearned but only worked for a short while. Problem is intermittent but gets progressively worse. Connector appears to be in good condition, wire inspection appears in good condition. Although I noticed a sensor just below the crank sensor slight towards the rear, above the exhaust that was unplugged. Not sure what it is, very small connected, looks 2 prong. Appeared to be on the transmission, was disoriented being middle of the night, and exhausted. Any ideas on that would be appreciated. As far as crank sensor im at a loss. Is there a service bulletin on them. Help. Start new job and need my car.