Transmission Control Module (TCM) Replacement: Notes
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2005 Isuzu Ascender, 2005 GMC Envoy XUV, 2005 GMC Envoy XL, 2005 GMC Envoy, and 2005 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
Service of the transmission control module (TCM) should consist of reprogramming of the TCM. If the diagnostic procedures call for the TCM to be replaced, the replacement TCM should be checked to ensure that the correct part is being used. If the correct part is being used, remove the faulty TCM and install the new service TCM. The replacement TCM must be programmed.