Theory Of Operation

The purpose of the diagnostic is to detect a failure in the activation of the pressure regulators and solenoids during gear disengagement or while position N or P is engaged. The pressure regulators are used to control the pressure to the clutches (B, C, D, and E). The solenoids are used to activate the pressure to the dog-clutches (A and F). The commanded currents calculated by the Transmission Control Module (TCM) to control the pressure regulators for the clutches and to activate the solenoids for the dog clutches are compared to the requested driving position from the shift-by-wire system.