Theory Of Operation

This diagnostic checks for the proper operation of the gate select and the four gear shift engagement actuators. The total number of performed operations and the number of failed operations by the gate select actuator and the four gear shift engagement actuators during a trip are accumulated in the internal memory of the Transmission Control Module (TCM). The registers in the internal memory which contain these counters are cleared after every trip. When the accumulated number of failed operations by the gate select actuator or by the four gear shift engagement actuators during a trip is greater than a corresponding threshold, this diagnostic will be considered failing.