Symptoms - Automatic Transmission: Notes

WARNING: This page is about a different car, the 2023 GMC Sierra 3500 HD and 2023 GMC Sierra 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Use the symptom tables only if the following conditions are met:

Refer to Diagnostic Starting Point - Vehicle .
There are no DTCs set.
The control modules can communicate via the serial data link.
Review the system operation in order to familiarize yourself with the system functions. Refer to Transmission General Description , and Transmission Component and System Description .