Action Taken When the DTC Sets

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

P0976

DTC P0976 is a Type C DTC.
The TCM defaults the transmission to 3rd gear or reverse gear.
The TCM forces the torque converter clutch (TCC) OFF.
The TCM commands maximum line pressure.
The TCM freezes transmission adaptive functions.
The TCM enables Torque Management.
The TCM inhibits TAP Up/Down function.
The TCM inhibits manual shifting of forward gears.

P0977

DTC P0977 is a Type A DTC.
The TCM inhibits 1st gear.
The TCM freezes transmission adaptive functions.
The TCM enables Torque Management.
The TCM inhibits TAP Up/Down function.
The TCM inhibits manual shifting of forward gears.