Although the driver has control of the shifting, the TCM will override the controls during some conditions. Sometimes, the TCM will force upshifts or prevent manual shifting. These conditions relate to the projected engine speed if a gear change does or does not take place. The Autostick feature will also be deactivated if the TCM senses problems and/or sets a trouble code that relates to the TR sensor or Autostick switch or when there is a high engine and transmission temperature code.