Transmission Will Not Stay in Forward or Reverse

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Condition	Action
Low fluid	Adjust the fluid level. Refer to Transmission Fluid Level and Condition Check .
Leaking at solenoid assembly	Replace the solenoid assembly. Refer to Control Valve Solenoid Replacement (SS1, SS2, SS3, TCC, and MAIN MOD) or Control Valve Solenoid Replacement (PCS1 and PCS2) .
Low pressure	Repair the transmission.
Faulty solenoid - leaking	Replace the solenoid. Refer to Control Valve Solenoid Replacement (SS1, SS2, SS3, TCC, and MAIN MOD) or Control Valve Solenoid Replacement (PCS1 and PCS2) .