Conditions for Setting the DTC
WARNING: This page is about a different car, the 2016 Cadillac CT6. However, it is still accessible from the selected car via links, so may be relevant.
DTC C0176 39
The power steering control module detects a failure of one of the two temperature sensors internal to the motor.
DTC C0176 54
The power steering control module detects a high system temperature.