WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
No TCC Release
Checks
Causes
TCC Solenoid (335)
Internal failure
A plugged fluid exhaust
An external ground
Torque Converter (55)
Internal failure
TCC Regulated Apply Valve (339) and TCC Control Valve (344)