Action Taken When the DTC Sets

WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The TCM illuminates the malfunction indicator lamp (MIL).
If the failure occurs while in a forward range, a shift to 1st, 3rd or 5th range is made.
While diagnostic response is active, if the shift selector is moved to NEUTRAL, the transmission will shift to NEUTRAL. If the shift selector is moved to REVERSE, the transmission will shift to REVERSE. If the shift selector is moved to a forward range or to REVERSE and the transmission is compromised by overspeeding or direction change, the transmission will shift to NEUTRAL.
DTC P0976 is stored in TCM history.
Main modulation (MAIN MOD) is inhibited.
The TCM freezes shift adapts.
The TCM inhibits torque converter clutch (TCC) engagement.