Conditions for Setting the DTC
WARNING: This page is about a different car, the 2011 GMC Yukon, 2011 Chevrolet Tahoe, and 2011 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
P0973
The control solenoid valve assembly detects an internal low voltage electrical malfunction of the shift solenoid 1 control circuit when shift solenoid 1 is commanded OFF for 1 second.
P0974
The control solenoid valve assembly detects an internal high voltage electrical malfunction of the shift solenoid 1 control circuit when shift solenoid 1 is commanded ON for 1 second.