Circuit/System Verification
WARNING: This page is about a different car, the 2009 GMC Sierra and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
If there are any other engine or transmission related DTCs set, diagnose those DTCs first. With a scan tool, observe the transmission output shaft speed sensor parameter for appropriate output RPM. Then in the engine controls data list, look for a functioning signal from the TCM.