Where is shift solenoid( A) located on a 3.1 Monte Carlo LS

Hello, Dave here, contributing to RepairPal and providing expert advice since 2010. Be very cautious. Diagnostic trouble codes give you symptoms - but do not suggest failures. Testing will be needed to reach the cause of the code setting. Replacing a "solenoid" is not likely going to solve anything, as valve body or hydraulic transmissions concerns are likely influencing the solenoids seen "failure" - and cannot be relied on to suggest a needed parts replacement. As an overview, the shift solenoid is located within the side transmission case cover. To remove this cover is a 5 hour job in a repair shop. It is not for the novice mechanic. Seek guidance at a shop near you for help diagnosing your concern. https://repairpal.com/auto-repair-near-me Click the link or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.