A method of providing a pretested electric shift control apparatus for a motor vehicle including an operator input push-button unit for mounting in the instrument panel of the motor vehicle, a power unit for mounting on the transmission of the motor vehicle, and a logic unit for mounting on the motor vehicle in a position in which it is electrically interconnected between the push-button unit and the power unit and operates to transmit operator input signals from the push-button unit to the power unit to shift the transmission to the position corresponding to the operator input. The method comprises the steps of manufacturing a plurality of push-button units; manufacturing a plurality of power units; manufacturing a plurality of logic units; providing a test assembly by assembling a push-button unit, a power unit, and a logic unit in a text fixture in a manner to simulate their assembled interrelationship on the motor vehicle; performing tests on the test assembly simulating the combined operation of the units on the motor vehicle; disassembling the test assembly into at least first and second tested modules; transporting the tested and disassembled modules to one or more motor vehicle manufacturing sites; and reassembling each tested first module on a motor vehicle in combination with a tested second module to provide a pretested electric shift control apparatus for the motor vehicle. A methodology is also disclosed for testing a shift control apparatus for shifting both the transmission and the transfer case of a four wheel drive motor vehicle.