Before removing the lid, unplug all connections to the controller.
Carefully remove the Function knob. Next, remove the 4 screws at the corners of the lid. Now the cover can be removed. Remember to fasten the cover back once the changes have been made to protect the circuit board.
In jumper location 1, is there a jumper installed on the highlighted pins?
This jumper should be installed for GM transmissions.
If there is no jumper, one will need to be installed. You can find them at most computer stores or you can contact BE Controls Tech Support for a no-cost replacement.